diff --git a/apps/editor/e2e/git.spec.ts b/apps/editor/e2e/git.spec.ts
index b9c0b5c3..f2e29039 100644
--- a/apps/editor/e2e/git.spec.ts
+++ b/apps/editor/e2e/git.spec.ts
@@ -77,24 +77,24 @@ test('git: VCS menu, commit panel, log, branches, remote, conflict, amend, stash
   await showPanel(page, 'Commit');
   await expect(commitPanel(page).getByText('This project is not a git repository')).toBeVisible();
   await vcs(page, 'Initialize repository');
-  await expect(group(page, 'Unversioned Files')).toBeVisible();
+  await expect(group(page, 'Unversioned files')).toBeVisible();
   git(PONG, 'config', 'user.name', 'E2E');
   git(PONG, 'config', 'user.email', 'e2e@example.com');
 
-  const nested = row(page, 'Unversioned Files', 'apps/client/src/main.ts');
+  const nested = row(page, 'Unversioned files', 'apps/client/src/main.ts');
   await expect(nested).toContainText('main.ts');
   await expect(nested).toContainText('apps/client/src');
   await message(page).fill('first commit');
   await expect(commitButton).toBeDisabled();
-  const includeAll = group(page, 'Unversioned Files').getByRole('checkbox', {
-    name: 'Include all: Unversioned Files',
+  const includeAll = group(page, 'Unversioned files').getByRole('checkbox', {
+    name: 'Include all: Unversioned files',
     includeHidden: true,
   });
   await nested.getByRole('checkbox').check();
   expect(await includeAll.evaluate((box: HTMLInputElement) => box.indeterminate)).toBe(true);
   await includeAll.check();
   await commit(page, 'first commit');
-  await expect(row(page, 'Unversioned Files', 'package.json')).toHaveCount(0);
+  await expect(row(page, 'Unversioned files', 'package.json')).toHaveCount(0);
   await expect(branchStatus(page, 'main')).toBeVisible();
 
   await showPanel(page, 'Git');
@@ -181,23 +181,23 @@ test('git: VCS menu, commit panel, log, branches, remote, conflict, amend, stash
   await page.keyboard.press('Space');
   await expect(changed.getByRole('checkbox')).toBeChecked();
   await changed.click({ button: 'right' });
-  await expect(page.getByRole('menuitem', { name: /^Show Diff/ })).toBeVisible();
-  await expect(page.getByRole('menuitem', { name: /^Jump to Source/ })).toBeVisible();
+  await expect(page.getByRole('menuitem', { name: /^Show diff/ })).toBeVisible();
+  await expect(page.getByRole('menuitem', { name: /^Jump to source/ })).toBeVisible();
   await page.getByRole('menuitem', { name: /^Rollback…/ }).click();
   await expect(page.getByRole('heading', { name: `Rollback ${FILE}?` })).toBeVisible();
   await page.getByRole('button', { name: 'Rollback', exact: true }).last().click();
   await expect(changed).toHaveCount(0);
   writeFileSync(join(PONG, NEW_FILE), 'new\n');
-  await row(page, 'Unversioned Files', NEW_FILE).click({ button: 'right' });
+  await row(page, 'Unversioned files', NEW_FILE).click({ button: 'right' });
   await page.getByRole('menuitem', { name: 'Add to VCS' }).click();
   await expect(row(page, 'Changes', NEW_FILE)).toBeVisible();
   await row(page, 'Changes', NEW_FILE).click();
   await rollBack.click();
   await page.getByRole('button', { name: 'Rollback', exact: true }).last().click();
-  await row(page, 'Unversioned Files', NEW_FILE).click();
+  await row(page, 'Unversioned files', NEW_FILE).click();
   await page.keyboard.press('Delete');
   await page.getByRole('button', { name: 'Delete', exact: true }).last().click();
-  await expect(row(page, 'Unversioned Files', NEW_FILE)).toHaveCount(0);
+  await expect(row(page, 'Unversioned files', NEW_FILE)).toHaveCount(0);
 
   await vcs(page, 'New branch…');
   await page.getByRole('textbox', { name: 'Branch name' }).fill('feature');
@@ -207,7 +207,7 @@ test('git: VCS menu, commit panel, log, branches, remote, conflict, amend, stash
   await local.getByRole('button', { name: 'main', exact: true }).dblclick();
   await expect(branchStatus(page, 'main')).toBeVisible();
   await local.getByRole('button', { name: 'feature', exact: true }).click({ button: 'right' });
-  await expect(page.getByRole('menuitem', { name: "New Branch from 'feature'…" })).toBeVisible();
+  await expect(page.getByRole('menuitem', { name: "New branch from 'feature'…" })).toBeVisible();
   await page.getByRole('menuitem', { name: 'Delete', exact: true }).click();
   await page.getByRole('button', { name: 'Delete', exact: true }).last().click();
   await expect(local.getByRole('button', { name: 'feature', exact: true })).toHaveCount(0);
@@ -229,7 +229,7 @@ test('git: VCS menu, commit panel, log, branches, remote, conflict, amend, stash
   writeFileSync(join(OTHER, FILE), 'theirs\n');
   git(OTHER, 'commit', '--quiet', '-am', 'their change');
   git(OTHER, 'push', '--quiet');
-  await logPanel(page).getByRole('button', { name: 'Fetch All Remotes' }).click();
+  await logPanel(page).getByRole('button', { name: 'Fetch all remotes' }).click();
   await expect(branchStatus(page, 'main ↓1')).toBeVisible();
   const remote = logPanel(page).getByRole('list', { name: 'Branches of origin' });
   await remote.getByRole('button', { name: 'main', exact: true }).click();
@@ -248,12 +248,12 @@ test('git: VCS menu, commit panel, log, branches, remote, conflict, amend, stash
   await expect(branchStatus(page, 'main ↑1 ↓1')).toBeVisible();
   await vcs(page, 'Update project');
   await expect(page.getByText('The update stopped on conflicts').last()).toBeVisible();
-  const conflict = row(page, 'Merge Conflicts', FILE);
+  const conflict = row(page, 'Merge conflicts', FILE);
   await expect(conflict).toBeVisible();
   writeFileSync(join(PONG, FILE), 'both\n');
   await conflict.getByRole('button', { name: 'Mark resolved' }).click();
-  await expect(group(page, 'Merge Conflicts')).toHaveCount(0);
-  await commit(page, 'merge', 'Commit and Push…');
+  await expect(group(page, 'Merge conflicts')).toHaveCount(0);
+  await commit(page, 'merge', 'Commit and push…');
   const afterMerge = await push();
   await expect(afterMerge.getByRole('list', { name: 'Commits to push' })).toContainText('merge');
   await afterMerge.getByRole('button', { name: 'Push', exact: true }).click();
@@ -267,7 +267,7 @@ test('git: VCS menu, commit panel, log, branches, remote, conflict, amend, stash
   await commit(page, 'merge, amended');
   await expect(commits(page).getByRole('row').first()).toContainText('merge, amended');
   await expect(changed).toHaveCount(0);
-  await commitPanel(page).getByRole('button', { name: 'Commit Message History' }).click();
+  await commitPanel(page).getByRole('button', { name: 'Commit message history' }).click();
   await page.getByRole('menuitem', { name: 'my change' }).click();
   await expect(message(page)).toHaveValue('my change');
   await message(page).fill('');
@@ -299,9 +299,9 @@ test('browses, folds and includes changes from the keyboard', async ({ page }) =
   await showPanel(page, 'Commit');
   await vcs(page, 'Initialize repository');
   const files = commitPanel(page).getByRole('group', { name: 'Changed files' });
-  const node = commitPanel(page).getByRole('button', { name: /^Unversioned Files, / });
+  const node = commitPanel(page).getByRole('button', { name: /^Unversioned files, / });
   const includeAll = commitPanel(page).getByRole('checkbox', {
-    name: 'Include all: Unversioned Files',
+    name: 'Include all: Unversioned files',
     includeHidden: true,
   });
   const active = () =>
@@ -314,7 +314,7 @@ test('browses, folds and includes changes from the keyboard', async ({ page }) =
   await page.keyboard.press('ArrowDown');
   await expect.poll(active).toMatch(/^Changes, 0 files/);
   await page.keyboard.press('ArrowDown');
-  await expect.poll(active).toMatch(/^Unversioned Files, /);
+  await expect.poll(active).toMatch(/^Unversioned files, /);
   await page.keyboard.press('Space');
   await expect(includeAll).toBeChecked();
   await page.keyboard.press('Space');
@@ -324,12 +324,12 @@ test('browses, folds and includes changes from the keyboard', async ({ page }) =
   await page.keyboard.press('ArrowRight');
   await expect(node).toHaveAttribute('aria-expanded', 'true');
   await page.keyboard.press('ArrowRight');
-  await expect.poll(active).not.toMatch(/^Unversioned Files/);
+  await expect.poll(active).not.toMatch(/^Unversioned files/);
   await expect(
-    group(page, 'Unversioned Files').getByRole('option', { selected: true }),
+    group(page, 'Unversioned files').getByRole('option', { selected: true }),
   ).toHaveCount(1);
   await page.keyboard.press('ArrowLeft');
-  await expect.poll(active).toMatch(/^Unversioned Files, /);
+  await expect.poll(active).toMatch(/^Unversioned files, /);
   await resetLayout(page);
   /** The layout is saved after 500 ms. */
   await page.waitForTimeout(900);
diff --git a/apps/editor/e2e/helpers.ts b/apps/editor/e2e/helpers.ts
index eb65c961..09571b6f 100644
--- a/apps/editor/e2e/helpers.ts
+++ b/apps/editor/e2e/helpers.ts
@@ -1,11 +1,14 @@
 import { type Page, expect } from '@playwright/test';
 
-/** Puts the saved layout of the project back to the default (tests reuse projects). */
+/**
+ * Puts the saved layout of the project back to the default with every panel (tests reuse
+ * projects, and expect the panels of the full layout).
+ */
 export const resetLayout = async (page: Page): Promise<void> => {
   await page.getByRole('button', { name: 'View', exact: true }).click();
   await page.getByRole('menuitem', { name: 'Layouts' }).click();
-  await page.getByRole('menuitem', { name: 'Reset layout' }).click();
-  await expect(page.getByText('Layout reset to default').last()).toBeVisible();
+  await page.getByRole('menuitem', { name: 'All panels' }).click();
+  await expect(page.getByText('Layout reset with all panels').last()).toBeVisible();
 };
 
 /** Expands folders of the Files tree, from the root (already expanded ones stay open). */
@@ -32,6 +35,12 @@ export const panelTab = (page: Page, name: string | RegExp) =>
  */
 export const showPanel = async (page: Page, name: string | RegExp): Promise<void> => {
   const tab = panelTab(page, name);
+  /** A panel the layout does not show (History, by default) opens from View › Panels. */
+  if (typeof name === 'string' && !(await tab.count())) {
+    await page.getByRole('button', { name: 'View', exact: true }).click();
+    await page.getByRole('menuitem', { name: 'Panels' }).click();
+    await page.getByRole('menuitem', { name, exact: true }).click();
+  }
   await expect(tab).toBeVisible();
   if ((await tab.getAttribute('aria-selected')) !== 'true') await tab.click();
   await expect(tab).toHaveAttribute('aria-selected', 'true');
diff --git a/apps/editor/e2e/history-panel.spec.ts b/apps/editor/e2e/history-panel.spec.ts
index aee2dbb4..b1bfa580 100644
--- a/apps/editor/e2e/history-panel.spec.ts
+++ b/apps/editor/e2e/history-panel.spec.ts
@@ -1,7 +1,7 @@
 import { existsSync } from 'node:fs';
 import { join } from 'node:path';
 
-import { openProject } from './helpers';
+import { openProject, resetLayout, showPanel } from './helpers';
 import { type Page, expect, test } from './test';
 import { PONG } from './workspace';
 
@@ -14,6 +14,9 @@ const row = (page: Page, name: string) => files(page).getByRole('treeitem', { na
 const open = async (page: Page) => {
   await openProject(page, 'pong');
   await page.waitForURL(/\/project\//);
+  await resetLayout(page);
+  /** History is not shown by default. */
+  await showPanel(page, 'History');
   await expect(row(page, 'apps')).toBeVisible();
 };
 
diff --git a/apps/editor/e2e/inspectors.spec.ts b/apps/editor/e2e/inspectors.spec.ts
index 2fa8f8c6..dd4812a9 100644
--- a/apps/editor/e2e/inspectors.spec.ts
+++ b/apps/editor/e2e/inspectors.spec.ts
@@ -101,14 +101,16 @@ test.describe('with the engine', () => {
 
     /** The count shown; screen readers get it only once a search has settled. */
     const count = page.getByText(/of \d+ packets/).first();
+    /**
+     * While hidden (still mounted), the panel records nothing: read its count twice while it is
+     * hidden, once the packets already on their way have landed.
+     */
     await showPanel(page, 'Console');
-    await page.waitForTimeout(1500);
-    await showPanel(page, 'Network');
+    await page.waitForTimeout(500);
     const before = await count.textContent();
-    await showPanel(page, 'Console');
     await page.waitForTimeout(2500);
-    await showPanel(page, 'Network');
     expect(await count.textContent()).toBe(before);
+    await showPanel(page, 'Network');
     await expect(page.getByRole('img', { name: 'Bytes per second' })).toBeVisible({
       timeout: 10_000,
     });
diff --git a/apps/editor/e2e/workbench.spec.ts b/apps/editor/e2e/workbench.spec.ts
index 321f71d0..cb53ca16 100644
--- a/apps/editor/e2e/workbench.spec.ts
+++ b/apps/editor/e2e/workbench.spec.ts
@@ -1,4 +1,4 @@
-import { expandFolders, openProject, panelTab, resetLayout } from './helpers';
+import { expandFolders, openProject, panelTab, resetLayout, showPanel } from './helpers';
 import { type Locator, type Page, expect, test } from './test';
 
 const openPong = async (page: Page) => {
@@ -55,6 +55,7 @@ test('moves, resizes and floats docks, undoes, and restores the layout after rel
 }) => {
   await openPong(page);
 
+  await showPanel(page, 'History');
   await drag(page, panelTab(page, 'History'), panelTab(page, 'Console'));
   await expect(stackOf(page, 'Console')).toHaveAttribute('data-slot', 'bottom');
   await expect(page.locator('[data-slot="bottom"][data-nf-drop="stack"]').first()).toHaveAttribute(
@@ -196,3 +197,39 @@ test('the project name in the status bar shows the Project screen, it no longer
   );
   await expect(page).toHaveURL(/\/project\//);
 });
+
+test('a simple layout shows the main panels only, all panels come back from the View menu', async ({
+  page,
+}) => {
+  await openPong(page);
+  const layouts = async (entry: string) => {
+    await page.getByRole('button', { name: 'View', exact: true }).click();
+    await page.getByRole('menuitem', { name: 'Layouts' }).click();
+    await page.getByRole('menuitem', { name: entry }).click();
+  };
+  const stripes = page.getByRole('navigation', { name: /tool windows$/ });
+  try {
+    await layouts('Simple layout');
+    await expect(page.getByText('Layout reset with the main panels').last()).toBeVisible();
+    for (const name of ['Files', 'Hierarchy', 'Inspector', 'Console'])
+      await expect(stripes.getByRole('tab', { name, exact: true })).toBeVisible();
+    for (const name of ['Commit', 'Profiler', 'History', 'Components'])
+      await expect(stripes.getByRole('tab', { name, exact: true })).toHaveCount(0);
+    await layouts('All panels');
+    await expect(stripes.getByRole('tab', { name: 'Commit', exact: true })).toBeVisible();
+  } finally {
+    await resetLayout(page);
+    await page.waitForTimeout(900);
+  }
+});
+
+test('says what each screen is for', async ({ page }) => {
+  await openPong(page);
+  const screens = page.getByRole('tablist', { name: 'Main screens' });
+  await expect(
+    screens.getByRole('tab', { name: 'Scene', exact: true }),
+  ).toHaveAccessibleDescription('Your entities drawn in 2D: select and move them.');
+  await expect(
+    screens.getByRole('tab', { name: 'Project', exact: true }),
+  ).toHaveAccessibleDescription(/apps and shared libraries/);
+});
diff --git a/apps/editor/src/lib/editor/error-description.ts b/apps/editor/src/lib/editor/error-description.ts
index c5d7be7c..063d0d82 100644
--- a/apps/editor/src/lib/editor/error-description.ts
+++ b/apps/editor/src/lib/editor/error-description.ts
@@ -1,5 +1,3 @@
-import { RpcError } from '@nanoforge-dev/editor-rpc';
-
 export interface ErrorAction {
   readonly label: string;
   readonly run: () => void | Promise<void>;
@@ -14,8 +12,5 @@ export interface ErrorDescription {
   readonly actions: readonly ErrorAction[];
 }
 
-export const errorCode = (reason: unknown): string | undefined =>
-  reason instanceof RpcError ? reason.code : (reason as { code?: string } | null)?.code;
-
 export const errorMessage = (reason: unknown): string =>
   reason instanceof Error ? reason.message : String(reason);
diff --git a/apps/editor/src/lib/project/register-core-panels.ts b/apps/editor/src/lib/project/register-core-panels.ts
index fc8e64a6..3fb0cf5c 100644
--- a/apps/editor/src/lib/project/register-core-panels.ts
+++ b/apps/editor/src/lib/project/register-core-panels.ts
@@ -18,6 +18,7 @@ const PANELS = [
   {
     id: 'core.project',
     title: 'Project',
+    description: 'Your apps and shared libraries, and what each one uses.',
     icon: 'layers',
     kind: 'screen',
     order: 100,
diff --git a/apps/editor/src/lib/workspace/workspace-actions.ts b/apps/editor/src/lib/workspace/workspace-actions.ts
index acdc2ad9..620d42ea 100644
--- a/apps/editor/src/lib/workspace/workspace-actions.ts
+++ b/apps/editor/src/lib/workspace/workspace-actions.ts
@@ -38,6 +38,8 @@ import {
 import { type AppModel, ProjectsContract } from '@nanoforge-dev/editor-protocol';
 import type { RpcClient } from '@nanoforge-dev/editor-rpc';
 import type { NotificationService, PromptService } from '@nanoforge-dev/editor-ui';
+/** The notification helpers alone: the kit's main entry brings its Svelte components. */
+import { notifyError } from '@nanoforge-dev/editor-ui/notification';
 
 /** Undo and redo target of the Project screen: changes of the workspace. */
 export const PROJECT_HISTORY_CONTEXT = 'project';
@@ -269,8 +271,8 @@ export class WorkspaceActions implements Disposable {
           detail: 'Its output is in the Console, under Tasks.',
         });
     } catch (error) {
-      notifications.notify('error', 'Could not install the dependencies', {
-        detail: error instanceof Error ? error.message : String(error),
+      notifyError(notifications, 'Could not install the dependencies', error, {
+        retry: () => this.install(),
       });
     }
   }
diff --git a/apps/editor/src/routes/(editor)/+layout.svelte b/apps/editor/src/routes/(editor)/+layout.svelte
index 7dc6e81f..04008872 100644
--- a/apps/editor/src/routes/(editor)/+layout.svelte
+++ b/apps/editor/src/routes/(editor)/+layout.svelte
@@ -1,10 +1,11 @@
 <script lang="ts">
+  import { errorCodeOf } from '@nanoforge-dev/editor-kernel';
   import type { Snippet } from 'svelte';
 
   import Loading from '$lib/editor/Loading.svelte';
   import { type Editor, createEditor } from '$lib/editor/create-editor';
   import { provideEditor } from '$lib/editor/editor-context';
-  import { type ErrorDescription, errorCode, errorMessage } from '$lib/editor/error-description';
+  import { type ErrorDescription, errorMessage } from '$lib/editor/error-description';
 
   const { children }: { children: Snippet } = $props();
 
@@ -19,14 +20,14 @@
 
   /** Startup failures, with what the user can do about them. */
   const describeStartupError = (reason: unknown): ErrorDescription =>
-    errorCode(reason) === 'TIMEOUT'
+    errorCodeOf(reason) === 'TIMEOUT'
       ? {
           title: 'The editor server does not answer',
           hint: 'It accepted the connection but sent nothing back. Restart it with nf editor, then try again.',
           detail: errorMessage(reason),
           actions: [retry],
         }
-      : errorCode(reason) === 'UNAVAILABLE'
+      : errorCodeOf(reason) === 'UNAVAILABLE'
         ? {
             title: "Can't reach the editor server",
             hint: 'Start it with nf editor in your project folder (or check your connection), then try again.',
diff --git a/apps/editor/src/routes/(editor)/load/+page.svelte b/apps/editor/src/routes/(editor)/load/+page.svelte
index 291bb722..55811333 100644
--- a/apps/editor/src/routes/(editor)/load/+page.svelte
+++ b/apps/editor/src/routes/(editor)/load/+page.svelte
@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { errorCodeOf } from '@nanoforge-dev/editor-kernel';
   import { goto } from '$app/navigation';
   import { page } from '$app/state';
   import type { ProjectRef } from '@nanoforge-dev/editor-protocol';
@@ -8,7 +9,6 @@
   import {
     type ErrorAction,
     type ErrorDescription,
-    errorCode,
     errorMessage,
   } from '$lib/editor/error-description';
 
@@ -55,7 +55,7 @@
   const describe = (reason: unknown, ref: ProjectRef): ErrorDescription => {
     const detail = errorMessage(reason);
     const name = 'path' in ref ? ref.path : 'this project';
-    switch (errorCode(reason)) {
+    switch (errorCodeOf(reason)) {
       case 'NOT_FOUND':
         return 'path' in ref
           ? {
diff --git a/apps/editor/src/routes/(editor)/project/[id]/+page.svelte b/apps/editor/src/routes/(editor)/project/[id]/+page.svelte
index 87642328..00b41c62 100644
--- a/apps/editor/src/routes/(editor)/project/[id]/+page.svelte
+++ b/apps/editor/src/routes/(editor)/project/[id]/+page.svelte
@@ -2,7 +2,7 @@
   import { goto } from '$app/navigation';
   import { page } from '$app/state';
   import { onDestroy } from 'svelte';
-  import { CoreServices, type Disposable } from '@nanoforge-dev/editor-kernel';
+  import { CoreServices, type Disposable, errorCodeOf } from '@nanoforge-dev/editor-kernel';
   import {
     LayoutControllerToken,
     Workbench,
@@ -16,7 +16,6 @@
   import {
     type ErrorAction,
     type ErrorDescription,
-    errorCode,
     errorMessage,
   } from '$lib/editor/error-description';
 
@@ -48,7 +47,7 @@
   /** Why the project could not open, and what the user can do about it. */
   const describe = async (reason: unknown, id: string): Promise<ErrorDescription> => {
     const detail = errorMessage(reason);
-    switch (errorCode(reason)) {
+    switch (errorCodeOf(reason)) {
       case 'NOT_FOUND': {
         const recent = await editor.projects.recent().catch(() => []);
         const known = recent.find((project) => project.id === id);
@@ -146,6 +145,7 @@
           resolve();
         });
       });
+      const recent = await editor.projects.recent().catch(() => []);
       if (disposed) return;
       created = setupWorkbench({
         shell: editor.shell,
@@ -157,6 +157,7 @@
         history: editor.history,
         logger: editor.services.get(CoreServices.Logger).getLogger('workbench'),
         activate: (event) => editor.plugins.activateByEvent(event),
+        knownUser: recent.some((project) => project.id !== id),
       });
       provided = [
         editor.services.provide(LayoutControllerToken, created.layout),
diff --git a/docs/docs/editor/git.mdx b/docs/docs/editor/git.mdx
index d57c837e..efc1e940 100644
--- a/docs/docs/editor/git.mdx
+++ b/docs/docs/editor/git.mdx
@@ -17,7 +17,7 @@ The **Commit** panel on the left lists what changed since the last commit, as fi
 
 1. **Check** the files to commit. A group's checkbox checks all its files.
 2. Write a message.
-3. **Commit**, or **Commit and Push…**
+3. **Commit**, or **Commit and push…**
 
 **Amend** replaces the last commit instead of adding one.
 
@@ -27,7 +27,7 @@ The **Commit** panel on the left lists what changed since the last commit, as fi
 | Undo your changes to files | Select them, then **Rollback**. It asks first: it cannot be undone. |
 | Start tracking a new file  | Right-click › Add to VCS                                            |
 | Ignore a file              | Right-click › Add to .gitignore                                     |
-| Put changes aside          | The **Stash** tab: Stash Changes, then Apply, Pop or Drop           |
+| Put changes aside          | The **Stash** tab: Stash changes, then Apply, Pop or Drop           |
 
 Checking a file only chooses what is committed. Selecting rows (click, `Ctrl`+click, `Shift`+click, or a click on a group to select all its files) is what Rollback and the other actions act on.
 
@@ -45,7 +45,7 @@ The status bar shows the branch and what is ahead and behind (`main ↑1 ↓2`).
 
 The **Git** panel at the bottom has three parts:
 
-- **Branches**: the current one, local ones, and remote ones. Double-click a branch to check it out. Right-click for _New Branch from…_, _Update_, _Push…_, _Delete_.
+- **Branches**: the current one, local ones, and remote ones. Double-click a branch to check it out. Right-click for _New branch from…_, _Update_, _Push…_, _Delete_.
 - **Commits** of the selected branch, with a filter by text, author and date.
 - **Changed files** of the selected commit, and its details. Double-click a file to compare.
 
@@ -57,7 +57,7 @@ Changed files are colored and carry a mark in the **Files** panel, and folders t
 
 ## Conflicts
 
-After an update that conflicts, the files show under **Merge Conflicts**. Open one, fix it in the code editor, then **Mark resolved**.
+After an update that conflicts, the files show under **Merge conflicts**. Open one, fix it in the code editor, then **Mark resolved**.
 
 <Note>
   Git works on the project's own repository only, and in local editors. Hosted projects are saved to
diff --git a/docs/docs/editor/layout.mdx b/docs/docs/editor/layout.mdx
index a4d8b77e..14026369 100644
--- a/docs/docs/editor/layout.mdx
+++ b/docs/docs/editor/layout.mdx
@@ -40,6 +40,7 @@ _View › Layouts_:
 
 - **Save layout** keeps the current arrangement under a name;
 - the saved layouts are listed there: choose one to switch to it;
+- **Simple layout** shows the main panels only (Files, Hierarchy, Scenes, Inspector, Console), **All panels** every one; each puts the layout back to that default, and becomes the default of _Reset layout_ (the setting _Default layout_). A new editor starts with the simple one.
 - **Reset layout** goes back to the default.
 
 Moving, closing, floating and resizing a panel are steps you can undo: `Ctrl+Z` with the focus on the layout, or in the **History** panel under _Layout_.
diff --git a/docs/docs/editor/overview.mdx b/docs/docs/editor/overview.mdx
index 437f6ec7..e2228374 100644
--- a/docs/docs/editor/overview.mdx
+++ b/docs/docs/editor/overview.mdx
@@ -75,7 +75,7 @@ Letters only need to be in order, not next to each other. The commands you ran l
 
 `Ctrl+Z` undoes the last change **of what has focus**: the file you edit, the Files panel, the layout. Each has its own history, so undoing a file move does not undo your code.
 
-The **History** panel lists the steps of what you are working on. Click a step to go back to it; the _All_ switch shows every history.
+The **History** panel (_View › Panels › History_) lists the steps of what you are working on. Click a step to go back to it; the _All_ switch shows every history.
 
 ## Problems and the status bar
 
diff --git a/docs/docs/getting-started/create-your-first-project.mdx b/docs/docs/getting-started/create-your-first-project.mdx
index fc90bc73..c6abaea5 100644
--- a/docs/docs/getting-started/create-your-first-project.mdx
+++ b/docs/docs/getting-started/create-your-first-project.mdx
@@ -34,11 +34,14 @@ A local editor can do what a hosted one cannot: run the game, use Git with your
 ![The editor](../images/editor-overview.png)
 
 - **Top**: the menu bar, the four main **screens** (Project, Scene, Script, Game), and the **Play** button.
-- **Left**: **Files**, the **Hierarchy** of entities and the **Commit** panel; below, **Components** and **Systems**.
-- **Right**: **History** and the **Inspector**.
-- **Bottom**: the **Console**, **Problems**, **Git**, and the **Profiler**, **Network** and **World** panels.
+- **Left**: **Files**, the **Hierarchy** of entities and, for games made of scenes, **Scenes**.
+- **Right**: the **Inspector**.
+- **Bottom**: the **Console**.
+
 - **Status bar**: the project, the count of problems, the Git branch, and the game's speed while it plays.
 
+The editor starts with these main panels only. _View › Layouts › All panels_ adds the others: **Commit**, **Components** and **Systems** on the left, **Problems**, **Git**, and the **Profiler**, **Network** and **World** panels at the bottom. _View › Panels_ opens any one of them, and the **History** of changes.
+
 Every panel can be moved, floated or closed: see [Layout](../editor/layout).
 
 ## Next
diff --git a/docs/docs/images/editor-overview.png b/docs/docs/images/editor-overview.png
index c111f33c..23d133b9 100644
Binary files a/docs/docs/images/editor-overview.png and b/docs/docs/images/editor-overview.png differ
diff --git a/docs/docs/plugins/create-your-first-plugin.mdx b/docs/docs/plugins/create-your-first-plugin.mdx
index 679dd91d..aa136485 100644
--- a/docs/docs/plugins/create-your-first-plugin.mdx
+++ b/docs/docs/plugins/create-your-first-plugin.mdx
@@ -41,7 +41,7 @@ In another terminal, start the editor with the plugin as a **dev plugin**:
 DEV_PLUGINS=/path/to/counter nf editor /path/to/a/project
 ```
 
-The Counter panel is in the bottom right dock. _View › Panels › Counter_ shows it again once closed. When you save a source file, the editor reloads the plugin without reloading the page.
+The Counter panel is in the bottom right dock. In the simple layout, which shows only the main panels, open it with _View › Panels › Counter_ (or _View › Layouts › All panels_); the same entry shows it again once closed. A plugin can put its panel in the simple layout with `"essential": true`, for the few panels most work needs. When you save a source file, the editor reloads the plugin without reloading the page.
 
 <Warning>
   `@nanoforge-dev/editor-sdk` and `@nanoforge-dev/editor-vite-plugin` are not published on npm yet,
diff --git a/docs/docs/plugins/manifest.mdx b/docs/docs/plugins/manifest.mdx
index 1b93e8e9..00268b8c 100644
--- a/docs/docs/plugins/manifest.mdx
+++ b/docs/docs/plugins/manifest.mdx
@@ -88,9 +88,11 @@ Panels (docks) and screens.
 | `title`          |         | **Required.** The tab's name.                                                          |
 | `icon`           |         | An icon name (`folder-tree`): a dock shows only the icon in its stripe.                |
 | `kind`           | `dock`  | `dock`: a panel in a dock or a floating window. `screen`: a main screen in the center. |
+| `description`    |         | Screens: one line on what it is for, shown in the screen tab's tooltip.                |
 | `defaultSlot`    |         | `leftTop`, `leftBottom`, `rightTop`, `rightBottom`, `bottom` or `bottomRight`.         |
 | `order`          | `0`     | Order among the tabs of the slot, or among screens.                                    |
 | `openByDefault`  | `true`  | Whether the default layout shows it.                                                   |
+| `essential`      | `false` | Whether the simple layout shows it too (the few panels most work needs).               |
 | `singleton`      | `true`  | One instance at a time.                                                                |
 | `when`           |         | Offered in menus only while true.                                                      |
 | `historyContext` |         | The history that undo and redo act on while the widget has focus.                      |
diff --git a/docs/usability-test.md b/docs/usability-test.md
new file mode 100644
index 00000000..cd6a50be
--- /dev/null
+++ b/docs/usability-test.md
@@ -0,0 +1,69 @@
+# Usability test
+
+Five people, five tasks, timed, before and after the simpler interfaces of M11. The numbers say whether M11 made the editor easier; the notes say where people still get stuck.
+
+## Builds
+
+Run the same five tasks on two builds, with different people for each (someone who did the tasks once is faster the second time, whatever the build).
+
+| Round  | What it is                                                                  |
+| ------ | --------------------------------------------------------------------------- |
+| Before | The editor before: every panel open, git labels in title case               |
+| After  | The simple layout, screens described, plain-language errors, History closed |
+
+For each round:
+
+```sh
+git switch <branch>
+pnpm install && pnpm turbo build --filter=@nanoforge-dev/editor...
+pnpm example breakout   # http://127.0.0.1:4800, engine from ../engine (NANOFORGE_ENGINE)
+```
+
+Before **each person** (stop the editor first):
+
+```sh
+rm -rf examples/.data                               # the editor's data: recent projects, account
+rm -f examples/breakout/.nanoforge/editor/local.json # breakout's saved layout (not in git)
+```
+
+and use a fresh browser profile (a private window), so each one starts from the editor's first run: the previous person's layout would otherwise spoil the comparison.
+
+## People
+
+Five people who make games but have not used this editor: students of the course are a good fit. Note for each one their experience with game engines (none, Unity/Godot, other) and with code editors.
+
+## Tasks
+
+Read each task aloud, then say nothing until they finish or give up (5 minutes per task at most). Ask them to think aloud.
+
+1. **Open the project.** "Open the breakout game: its folder is `breakout`." (The list of recent projects is empty on a first run.)
+2. **Add an entity.** "In the Level 1 scene, add a new brick entity." (It must end up in the scene's code.)
+3. **Change a value.** "Make the ball start faster." (Any velocity change on the ball counts.)
+4. **Play.** "Play the game, then stop it."
+5. **Commit.** "Save your work in Git with the message `faster ball`." (The project must be a repository: run `git init && git add -A && git commit -m start` in `examples/breakout` before the session.)
+
+## What to record
+
+For each person and task:
+
+| Measure | How                                                                         |
+| ------- | --------------------------------------------------------------------------- |
+| Time    | From the end of the instruction to the result on screen (or the give-up)    |
+| Done    | Yes, with help (you had to say something), or no                            |
+| Errors  | Wrong turns: a wrong panel or menu opened, an action undone, an error shown |
+| Notes   | What they looked for and where, what they said, what they misread           |
+
+A sheet per round:
+
+| Person | Experience | Task | Time (s) | Done | Errors | Notes |
+| ------ | ---------- | ---- | -------- | ---- | ------ | ----- |
+|        |            | 1    |          |      |        |       |
+
+## Reading the results
+
+- Compare the median time and the success rate of each task between the rounds; with five people per round, only large differences mean something.
+- The notes matter more than the times: a place where three people looked for the same thing is worth fixing whatever the numbers say.
+
+## After the session
+
+Remove `examples/breakout/.git` and `examples/.data`, and put back anything the people changed in `examples/breakout` (`git checkout examples/breakout`).
diff --git a/packages/kernel/src/error/error-code-of.ts b/packages/kernel/src/error/error-code-of.ts
new file mode 100644
index 00000000..7827f657
--- /dev/null
+++ b/packages/kernel/src/error/error-code-of.ts
@@ -0,0 +1,5 @@
+/** The code of an editor error (an RPC error, or anything with a string `code`). */
+export const errorCodeOf = (error: unknown): string | undefined => {
+  const code = (error as { code?: unknown } | null)?.code;
+  return typeof code === 'string' ? code : undefined;
+};
diff --git a/packages/kernel/src/error/index.ts b/packages/kernel/src/error/index.ts
new file mode 100644
index 00000000..6a60452d
--- /dev/null
+++ b/packages/kernel/src/error/index.ts
@@ -0,0 +1 @@
+export * from './error-code-of';
diff --git a/packages/kernel/src/index.ts b/packages/kernel/src/index.ts
index b92bc9e7..61613cfc 100644
--- a/packages/kernel/src/index.ts
+++ b/packages/kernel/src/index.ts
@@ -1,6 +1,7 @@
 export * from './command';
 export * from './context';
 export * from './di';
+export * from './error';
 export * from './event';
 export * from './extension';
 export * from './i18n';
diff --git a/packages/layout/src/default/default-layout.ts b/packages/layout/src/default/default-layout.ts
index 3b408fd7..a2ff331c 100644
--- a/packages/layout/src/default/default-layout.ts
+++ b/packages/layout/src/default/default-layout.ts
@@ -13,15 +13,31 @@ export interface WidgetPlacement {
   readonly order?: number;
   /** Docks: shown in the default layout (default true). */
   readonly openByDefault?: boolean;
+  /** Docks: shown in the simple layout too (the few panels most work needs). */
+  readonly essential?: boolean;
 }
 
-/** The layout used when nothing is saved: screens in order, docks in their default slots. */
-export const composeDefaultLayout = (widgets: readonly WidgetPlacement[]): Layout => {
+/** `simple`: only the essential docks; `full`: every dock open by default. */
+export type LayoutPreset = 'simple' | 'full';
+
+/**
+ * The layout used when nothing is saved: screens in order, docks in their default slots. With
+ * the `simple` preset, only the docks marked `essential`; the others stay in View › Panels.
+ */
+export const composeDefaultLayout = (
+  widgets: readonly WidgetPlacement[],
+  preset: LayoutPreset = 'full',
+): Layout => {
   const byOrder = (a: WidgetPlacement, b: WidgetPlacement) =>
     (a.order ?? 0) - (b.order ?? 0) || a.id.localeCompare(b.id);
   const screens = widgets.filter((widget) => widget.kind === 'screen').sort(byOrder);
   const docks = widgets
-    .filter((widget) => widget.kind === 'dock' && widget.openByDefault !== false)
+    .filter(
+      (widget) =>
+        widget.kind === 'dock' &&
+        widget.openByDefault !== false &&
+        (preset === 'full' || widget.essential === true),
+    )
     .sort(byOrder);
   const ops: LayoutOp[] = [{ type: 'setScreens', screens: screens.map((screen) => screen.id) }];
   const counts: Partial<Record<SlotId, number>> = {};
diff --git a/packages/layout/test/default/default-layout.spec.ts b/packages/layout/test/default/default-layout.spec.ts
index 5d3be202..5145606f 100644
--- a/packages/layout/test/default/default-layout.spec.ts
+++ b/packages/layout/test/default/default-layout.spec.ts
@@ -1,6 +1,12 @@
 import { describe, expect, it } from 'vitest';
 
-import { allWidgets, deserializeLayout, reconcileLayout, serializeLayout } from '../../src';
+import {
+  allWidgets,
+  composeDefaultLayout,
+  deserializeLayout,
+  reconcileLayout,
+  serializeLayout,
+} from '../../src';
 import { apply, base, widgets } from '../fixtures/layout';
 
 describe('default layout', () => {
@@ -18,6 +24,31 @@ describe('default layout', () => {
     expect(allWidgets(layout).map((ref) => ref.instanceId)).not.toContain('profiler');
   });
 
+  it('opens only the essential docks with the simple preset, and keeps the others out', () => {
+    const marked = widgets.map((widget) =>
+      widget.id === 'files' || widget.id === 'inspector' ? { ...widget, essential: true } : widget,
+    );
+    const simple = composeDefaultLayout(marked, 'simple');
+    expect(
+      allWidgets(simple)
+        .map((ref) => ref.widgetId)
+        .sort(),
+    ).toEqual(['files', 'inspector']);
+    expect(simple.screens).toEqual(['scene', 'script', 'game']);
+    expect(simple.known).toContain('console');
+
+    const reloaded = deserializeLayout(serializeLayout(simple))!;
+    const known = new Set(reloaded.known ?? []);
+    const withPlugin = reconcileLayout(
+      reloaded,
+      [...marked, { id: 'network', kind: 'dock', defaultSlot: 'bottom' }],
+      known,
+    );
+    const shown = allWidgets(withPlugin).map((ref) => ref.widgetId);
+    expect(shown).not.toContain('console');
+    expect(shown).toContain('network');
+  });
+
   it('keeps a closed dock closed after a reload', () => {
     const closed = apply(base(), { type: 'remove', instanceId: 'console' });
     const reloaded = deserializeLayout(serializeLayout(closed))!;
diff --git a/packages/sdk/src/index.ts b/packages/sdk/src/index.ts
index 7a3aa143..133c7969 100644
--- a/packages/sdk/src/index.ts
+++ b/packages/sdk/src/index.ts
@@ -77,6 +77,7 @@ export {
   PluginHostToken,
   type PluginInfo,
   switchObservable,
+  errorCodeOf,
 } from '@nanoforge-dev/editor-kernel';
 
 export {
diff --git a/packages/sdk/src/ui.ts b/packages/sdk/src/ui.ts
index bd4596e5..558d2105 100644
--- a/packages/sdk/src/ui.ts
+++ b/packages/sdk/src/ui.ts
@@ -118,5 +118,8 @@ export {
   Vector2Input,
   isKeyboardMenu,
   moveRowFocus,
+  describeError,
+  notifyError,
+  type ErrorExplanation,
   moveTabFocus,
 } from '@nanoforge-dev/editor-ui';
diff --git a/packages/sdk/test/index.spec.ts b/packages/sdk/test/index.spec.ts
index 7e7acb79..ad876fa0 100644
--- a/packages/sdk/test/index.spec.ts
+++ b/packages/sdk/test/index.spec.ts
@@ -88,6 +88,7 @@ describe('public API', () => {
         "disposeAll",
         "documentHistoryId",
         "editorsFor",
+        "errorCodeOf",
         "formatLogValue",
         "formatMessage",
         "isDisposable",
diff --git a/packages/settings/src/account-sync/account-sync-store.ts b/packages/settings/src/account-sync/account-sync-store.ts
index 80ee9d3b..fe8605a6 100644
--- a/packages/settings/src/account-sync/account-sync-store.ts
+++ b/packages/settings/src/account-sync/account-sync-store.ts
@@ -3,6 +3,7 @@ import {
   type Observable,
   ObservableValue,
   createToken,
+  errorCodeOf,
 } from '@nanoforge-dev/editor-kernel';
 import { SETTINGS_LIMITS } from '@nanoforge-dev/editor-protocol';
 
@@ -24,7 +25,6 @@ interface PersistedState {
   dirty: boolean;
 }
 
-const errorCode = (error: unknown) => (error as { code?: string } | null)?.code;
 const OFFLINE_CODES = new Set(['UNAVAILABLE', 'TIMEOUT']);
 
 /**
@@ -152,7 +152,7 @@ export class AccountSyncStore implements ScopeStore {
         this._conflicts.get().length ? 'conflict' : this._state.dirty ? 'pending' : 'idle',
       );
     } catch (error) {
-      if (OFFLINE_CODES.has(errorCode(error) ?? '') || error instanceof TypeError) {
+      if (OFFLINE_CODES.has(errorCodeOf(error) ?? '') || error instanceof TypeError) {
         this._status.set('offline');
         const delays = this._options.retryDelays ?? [1000, 2000, 5000, 15_000, 60_000];
         this._schedule(delays[Math.min(this._attempt++, delays.length - 1)]!);
@@ -206,7 +206,7 @@ export class AccountSyncStore implements ScopeStore {
       await this._persist();
       if (dirty) this._rerun = true;
     } catch (error) {
-      if (errorCode(error) !== 'CONFLICT' || attempt >= 3) throw error;
+      if (errorCodeOf(error) !== 'CONFLICT' || attempt >= 3) throw error;
       const remote = (error as { data?: AccountDocument }).data ?? (await this._remote.get());
       this._rebase(remote);
       this._rerun = false;
diff --git a/packages/settings/src/definition/core-settings.ts b/packages/settings/src/definition/core-settings.ts
index 664cd065..8895fd8a 100644
--- a/packages/settings/src/definition/core-settings.ts
+++ b/packages/settings/src/definition/core-settings.ts
@@ -58,6 +58,16 @@ export const CoreSettings = {
     description: 'Consecutive changes of the same value within this delay (ms) are one undo step.',
     category: 'Editor/History',
   }),
+  layoutPreset: defineSetting({
+    key: 'layout.preset',
+    schema: z.enum(['simple', 'full']),
+    default: 'simple',
+    title: 'Default layout',
+    description:
+      'Simple shows only the main panels (files, hierarchy, scenes, inspector, console); All panels shows every one. Used when a layout is reset or none is saved yet.',
+    category: 'Editor/Layout',
+    scopes: ['account', 'machine'],
+  }),
   layoutActive: defineSetting({
     key: 'layout.active',
     schema: z.string(),
diff --git a/packages/settings/src/store/json-file.scope-store.ts b/packages/settings/src/store/json-file.scope-store.ts
index 890ef681..8e1d37f9 100644
--- a/packages/settings/src/store/json-file.scope-store.ts
+++ b/packages/settings/src/store/json-file.scope-store.ts
@@ -1,10 +1,15 @@
-import { DisposableStore, type Observable, ObservableValue } from '@nanoforge-dev/editor-kernel';
+import {
+  DisposableStore,
+  type Observable,
+  ObservableValue,
+  errorCodeOf,
+} from '@nanoforge-dev/editor-kernel';
 
 import type { ScopeStore, SettingValues, TextFileAdapter } from './scope-store.type';
 import { applyPatch, serializeValues } from './setting-values';
 import { SettingsFileError } from './settings-file.exception';
 
-const isConflict = (error: unknown) => (error as { code?: string } | null)?.code === 'CONFLICT';
+const isConflict = (error: unknown) => errorCodeOf(error) === 'CONFLICT';
 
 /**
  * Scope stored as a JSON object in a file. Edits made outside the editor are picked up; a
diff --git a/packages/ui/package.json b/packages/ui/package.json
index a514fce7..18622d9d 100644
--- a/packages/ui/package.json
+++ b/packages/ui/package.json
@@ -24,6 +24,7 @@
       "default": "./src/index.ts"
     },
     "./fonts.css": "./src/theme/fonts.css",
+    "./notification": "./src/workbench/notification/index.ts",
     "./package.json": "./package.json"
   },
   "type": "module",
diff --git a/packages/ui/src/components/toasts.svelte b/packages/ui/src/components/toasts.svelte
index 8b7f9353..ae681a1a 100644
--- a/packages/ui/src/components/toasts.svelte
+++ b/packages/ui/src/components/toasts.svelte
@@ -55,6 +55,12 @@
       <div class="body">
         <p class="message">{notification.message}</p>
         {#if notification.detail}<p class="detail">{notification.detail}</p>{/if}
+        {#if notification.technical}
+          <details class="technical">
+            <summary>Show details</summary>
+            <pre>{notification.technical}</pre>
+          </details>
+        {/if}
         {#if notification.actions.length}
           <div class="actions">
             {#each notification.actions as action (action.title)}
@@ -120,6 +126,18 @@
   .message {
     margin: 2px 0 0;
   }
+  .technical {
+    margin: var(--nf-space-1) 0 0;
+    color: var(--nf-color-text-muted);
+    font-size: var(--nf-font-size-sm);
+  }
+  .technical pre {
+    max-height: 8em;
+    margin: var(--nf-space-1) 0 0;
+    overflow: auto;
+    white-space: pre-wrap;
+    word-break: break-word;
+  }
   .detail {
     margin: 2px 0 0;
     color: var(--nf-color-text-muted);
diff --git a/packages/ui/src/workbench/extension-point/widget.extension-point.ts b/packages/ui/src/workbench/extension-point/widget.extension-point.ts
index 91b52702..748dbdac 100644
--- a/packages/ui/src/workbench/extension-point/widget.extension-point.ts
+++ b/packages/ui/src/workbench/extension-point/widget.extension-point.ts
@@ -17,11 +17,15 @@ export const WidgetDescriptorSchema = z.object({
   title: z.string().min(1),
   /** Lucide icon name, e.g. `folder-tree`. */
   icon: z.string().optional(),
+  /** One line on what it is for (screens: shown when the pointer or the focus is on its tab). */
+  description: z.string().optional(),
   /** `screen`: main screen in the center; `dock`: panel in a dock slot or floating window. */
   kind: z.enum(['dock', 'screen']).default('dock'),
   defaultSlot: SLOT.optional(),
   order: z.number().default(0),
   openByDefault: z.boolean().default(true),
+  /** Docks: part of the simple layout, the few panels most work needs. */
+  essential: z.boolean().default(false),
   /** Only one instance at a time (default). */
   singleton: z.boolean().default(true),
   /** Offered in menus only when true. */
diff --git a/packages/ui/src/workbench/layout/layout-controller.ts b/packages/ui/src/workbench/layout/layout-controller.ts
index e6d0a3f4..f174fd57 100644
--- a/packages/ui/src/workbench/layout/layout-controller.ts
+++ b/packages/ui/src/workbench/layout/layout-controller.ts
@@ -10,6 +10,7 @@ import {
   type Layout,
   LayoutError,
   type LayoutOp,
+  type LayoutPreset,
   type Location,
   type SlotId,
   allWidgets,
@@ -52,6 +53,8 @@ export class LayoutController implements Disposable {
   private readonly _store = new DisposableStore();
   private readonly _history: HistoryContext;
   private _saveTimer: ReturnType<typeof setTimeout> | undefined;
+  /** No layout was saved yet: the preset's default was used (offer the other one). */
+  firstRun = false;
   private _floatCounter = 0;
   private readonly _docksHidden = new ObservableValue(false);
 
@@ -232,9 +235,9 @@ export class LayoutController implements Disposable {
     await this._history.stack.clear();
   }
 
-  /** Back to the default layout of the installed widgets. */
-  async reset(): Promise<void> {
-    this._set(composeDefaultLayout(this._widgets()));
+  /** Back to the default layout of the installed widgets (`layout.preset`, or the one given). */
+  async reset(preset?: LayoutPreset): Promise<void> {
+    this._set(composeDefaultLayout(this._widgets(), preset ?? this._preset()));
     await this._history.stack.clear();
   }
 
@@ -281,7 +284,9 @@ export class LayoutController implements Disposable {
   private _load(): Layout {
     const saved = this._saved()[this._activeName()];
     const layout = saved === undefined ? undefined : deserializeLayout(saved);
-    return layout ? this._reconcile(layout) : composeDefaultLayout(this._widgets());
+    if (layout) return this._reconcile(layout);
+    this.firstRun = true;
+    return composeDefaultLayout(this._widgets(), this._preset());
   }
 
   private _reconcile(layout: Layout): Layout {
@@ -294,6 +299,10 @@ export class LayoutController implements Disposable {
     return this._options.settings.hasStore('projectLocal') ? 'projectLocal' : 'account';
   }
 
+  private _preset(): LayoutPreset {
+    return this._options.settings.get(CoreSettings.layoutPreset) === 'full' ? 'full' : 'simple';
+  }
+
   private _saved(): Record<string, unknown> {
     return this._options.settings.get(CoreSettings.layoutSaved) as Record<string, unknown>;
   }
diff --git a/packages/ui/src/workbench/notification/describe-error.ts b/packages/ui/src/workbench/notification/describe-error.ts
new file mode 100644
index 00000000..a3ce246e
--- /dev/null
+++ b/packages/ui/src/workbench/notification/describe-error.ts
@@ -0,0 +1,69 @@
+import { errorCodeOf } from '@nanoforge-dev/editor-kernel';
+
+import type { NotificationAction, NotificationService } from './notification-service';
+
+/** An error said in plain words, with what can be done about it. */
+export interface ErrorExplanation {
+  /** What happened, for anyone (`undefined`: the raw message is already plain). */
+  readonly hint: string | undefined;
+  /** The raw message, kept for Show details. */
+  readonly technical: string;
+  /** Whether trying the same thing again may work (the server was away, a request timed out). */
+  readonly retryable: boolean;
+}
+
+/**
+ * Codes whose raw message is technical. The others (CONFLICT, FORBIDDEN, NOT_FOUND…) carry the
+ * server's own words, already plain and more precise than a hint per code would be ("Already
+ * exists: a.ts", "Permission denied: b.ts"): they are shown as they are. A TIMEOUT says what
+ * timed out and what to do (git's "no answer from the remote"), so it has no hint either.
+ */
+const HINTS: Record<string, { hint?: string; retryable: boolean }> = {
+  UNAVAILABLE: {
+    hint: "The editor server can't be reached. Your changes are kept: try again once it is back.",
+    retryable: true,
+  },
+  TIMEOUT: { retryable: true },
+  UNAUTHORIZED: { hint: 'Your session expired: sign in again.', retryable: false },
+  INTERNAL: { retryable: false },
+};
+
+/**
+ * The editor server's message for an error it did not expect (`toRpcError`). An INTERNAL error
+ * with another message carries its own words (git's stderr): those are shown as they are.
+ */
+const UNEXPECTED_MESSAGE = 'Internal error';
+const UNEXPECTED_HINT = 'Something went wrong in the editor server. Show details tells what.';
+
+export const describeError = (error: unknown): ErrorExplanation => {
+  const technical = error instanceof Error ? error.message : String(error);
+  const code = errorCodeOf(error);
+  const known = HINTS[code ?? ''];
+  const hint =
+    code === 'INTERNAL' && technical === UNEXPECTED_MESSAGE ? UNEXPECTED_HINT : known?.hint;
+  return { hint, technical, retryable: known?.retryable ?? false };
+};
+
+/**
+ * Shows an error as a sentence and what to do: `title` says what failed, the explanation why;
+ * the raw message stays behind Show details. `retry` is offered only when the error says trying
+ * again may work, and only if the operation is safe to repeat (the caller decides).
+ */
+export const notifyError = (
+  notifications: NotificationService | undefined,
+  title: string,
+  error: unknown,
+  options: {
+    readonly retry?: () => void | Promise<void>;
+    readonly actions?: readonly NotificationAction[];
+  } = {},
+): void => {
+  const { hint, technical, retryable } = describeError(error);
+  notifications?.notify('error', title, {
+    ...(hint ? { detail: hint, technical } : { detail: technical }),
+    actions: [
+      ...(retryable && options.retry ? [{ title: 'Try again', run: options.retry }] : []),
+      ...(options.actions ?? []),
+    ],
+  });
+};
diff --git a/packages/ui/src/workbench/notification/index.ts b/packages/ui/src/workbench/notification/index.ts
index 5ce85c27..c6c63301 100644
--- a/packages/ui/src/workbench/notification/index.ts
+++ b/packages/ui/src/workbench/notification/index.ts
@@ -1 +1,2 @@
 export * from './notification-service';
+export * from './describe-error';
diff --git a/packages/ui/src/workbench/notification/notification-service.ts b/packages/ui/src/workbench/notification/notification-service.ts
index 6efc6d88..08318689 100644
--- a/packages/ui/src/workbench/notification/notification-service.ts
+++ b/packages/ui/src/workbench/notification/notification-service.ts
@@ -12,6 +12,8 @@ export interface Notification {
   readonly severity: Severity;
   readonly message: string;
   readonly detail?: string;
+  /** The raw error, behind Show details: the message and `detail` say it in plain words. */
+  readonly technical?: string;
   readonly actions: readonly NotificationAction[];
   readonly source?: string;
   readonly time: number;
@@ -19,6 +21,7 @@ export interface Notification {
 
 export interface NotifyOptions {
   readonly detail?: string;
+  readonly technical?: string;
   readonly actions?: readonly NotificationAction[];
   readonly source?: string;
   /** Auto dismiss delay in ms; errors stay until dismissed. Default 5000 (0 = sticky). */
@@ -60,6 +63,7 @@ export class NotificationService {
       actions: options.actions ?? [],
       time: Date.now(),
       ...(options.detail && { detail: options.detail }),
+      ...(options.technical && { technical: options.technical }),
       ...(options.source && { source: options.source }),
     };
     this._active.update((list) => [...list, notification]);
diff --git a/packages/ui/src/workbench/parts/StatusBar.svelte b/packages/ui/src/workbench/parts/StatusBar.svelte
index a1a070cd..0e1f6dc8 100644
--- a/packages/ui/src/workbench/parts/StatusBar.svelte
+++ b/packages/ui/src/workbench/parts/StatusBar.svelte
@@ -78,10 +78,19 @@
             >
           </header>
           {#each $history as notification (notification.id)}
-            <p class="entry {notification.severity}">
-              <time>{time(notification.time)}</time>
-              {notification.message}
-            </p>
+            <div class="entry {notification.severity}">
+              <p>
+                <time>{time(notification.time)}</time>
+                {notification.message}
+              </p>
+              {#if notification.detail}<p class="entry-detail">{notification.detail}</p>{/if}
+              {#if notification.technical}
+                <details class="entry-detail">
+                  <summary>Show details</summary>
+                  <pre>{notification.technical}</pre>
+                </details>
+              {/if}
+            </div>
           {:else}
             <p class="none">No notifications</p>
           {/each}
@@ -140,9 +149,22 @@
     padding: 6px 4px;
     border-top: 1px solid var(--nf-color-border);
   }
-  :global(.notification-center .error) {
+  :global(.notification-center .entry p) {
+    margin: 0;
+  }
+  :global(.notification-center .error > p:first-child) {
     color: var(--nf-color-danger);
   }
+  :global(.notification-center .entry-detail) {
+    margin: 2px 0 0;
+    color: var(--nf-color-text-muted);
+    font-size: var(--nf-font-size-sm);
+  }
+  :global(.notification-center .entry-detail pre) {
+    margin: 2px 0 0;
+    white-space: pre-wrap;
+    word-break: break-word;
+  }
   :global(.notification-center time) {
     margin-right: 6px;
     color: var(--nf-color-text-faint);
diff --git a/packages/ui/src/workbench/parts/TopBar.svelte b/packages/ui/src/workbench/parts/TopBar.svelte
index 374c44c8..2d1074ac 100644
--- a/packages/ui/src/workbench/parts/TopBar.svelte
+++ b/packages/ui/src/workbench/parts/TopBar.svelte
@@ -8,6 +8,7 @@
   import { TOOLBAR_ITEMS } from '../extension-point/toolbar.extension-point';
   import { formatKeybinding } from '../keybinding/keystroke';
   import { getWorkbenchContext } from '../workbench-context';
+  import Tooltip from '../../components/tooltip.svelte';
   import MenuBarMenu from './MenuBarMenu.svelte';
 
   const { layout: current, brand }: { layout: Layout; brand?: Snippet } = $props();
@@ -39,6 +40,8 @@
   });
 
   const screenTitle = (id: string) => context.workbench.descriptor(id)?.title ?? id;
+  const screenDescription = (id: string) => context.workbench.descriptor(id)?.description;
+  const uid = $props.id();
   const screenIcon = (id: string) => context.workbench.descriptor(id)?.icon;
 
   const onkeydown = (event: KeyboardEvent) => {
@@ -67,18 +70,31 @@
 
   <div class="screens" role="tablist" aria-label="Main screens" tabindex="-1" {onkeydown}>
     {#each current.screens as screen (screen)}
-      <button
-        type="button"
-        role="tab"
-        class="screen"
-        data-screen={screen}
-        aria-selected={current.activeScreen === screen}
-        tabindex={current.activeScreen === screen ? 0 : -1}
-        onclick={() => context.layout.showScreen(screen)}
-      >
-        {#if screenIcon(screen)}<Icon name={screenIcon(screen)} size={15} />{/if}
-        {screenTitle(screen)}
-      </button>
+      {@const description = screenDescription(screen)}
+      {#snippet tab(props: Record<string, unknown>)}
+        <button
+          {...props}
+          type="button"
+          role="tab"
+          class="screen"
+          data-screen={screen}
+          aria-selected={current.activeScreen === screen}
+          aria-describedby={description ? `${uid}-${screen}` : undefined}
+          tabindex={current.activeScreen === screen ? 0 : -1}
+          onclick={() => context.layout.showScreen(screen)}
+        >
+          {#if screenIcon(screen)}<Icon name={screenIcon(screen)} size={15} />{/if}
+          {screenTitle(screen)}
+        </button>
+      {/snippet}
+      {#if description}
+        <Tooltip text={description} side="bottom">
+          {#snippet children({ props })}{@render tab(props)}{/snippet}
+        </Tooltip>
+        <span id={`${uid}-${screen}`} hidden>{description}</span>
+      {:else}
+        {@render tab({})}
+      {/if}
     {/each}
   </div>
 
diff --git a/packages/ui/src/workbench/service/workbench-service.ts b/packages/ui/src/workbench/service/workbench-service.ts
index 042120fa..228d70a7 100644
--- a/packages/ui/src/workbench/service/workbench-service.ts
+++ b/packages/ui/src/workbench/service/workbench-service.ts
@@ -140,6 +140,7 @@ export class WorkbenchService implements Disposable {
       kind: 'dock' as const,
       order: 0,
       openByDefault: false,
+      essential: false,
       singleton: true,
     };
     const record: InstanceRecord = {
diff --git a/packages/ui/src/workbench/setup/setup-workbench.ts b/packages/ui/src/workbench/setup/setup-workbench.ts
index f696e979..5a19cec3 100644
--- a/packages/ui/src/workbench/setup/setup-workbench.ts
+++ b/packages/ui/src/workbench/setup/setup-workbench.ts
@@ -32,7 +32,11 @@ export interface WorkbenchSetupOptions {
   readonly settings: SettingsService;
   readonly history: HistoryService;
   readonly logger: Logger;
-  /** Activates plugins (`onWidget:<id>`). */
+  /**
+   * The user worked in other projects before (the recent projects list): with no default layout
+   * chosen yet, they used the editor before presets and keep every panel.
+   */
+  readonly knownUser?: boolean;
   /** Activates the plugins of an event; may resolve with their failures (to explain a panel). */
   readonly activate: (event: string) => Promise<unknown>;
 }
@@ -103,6 +107,54 @@ export const setupWorkbench = (options: WorkbenchSetupOptions): WorkbenchContext
     await layout.reset();
     shell.notifications.notify('info', 'Layout reset to default');
   });
+  /** Where to write the default layout: the scope that holds it now, so no other one outranks it. */
+  const presetScope = (): 'account' | 'machine' => {
+    const { effectiveScope } = settings.inspect(CoreSettings.layoutPreset);
+    if (effectiveScope === 'account' || effectiveScope === 'machine') return effectiveScope;
+    return settings.hasStore('account') ? 'account' : 'machine';
+  };
+  /** Switches the default layout and resets to it (the layout's undo history starts over). */
+  const usePreset = async (preset: 'simple' | 'full') => {
+    await settings.set(CoreSettings.layoutPreset, preset, presetScope());
+    await layout.reset(preset);
+    shell.notifications.notify(
+      'info',
+      preset === 'full' ? 'Layout reset with all panels' : 'Layout reset with the main panels',
+    );
+  };
+  register('layout.simple', 'Simple layout', () => usePreset('simple'));
+  register('layout.full', 'All panels', () => usePreset('full'));
+  /**
+   * The default layout is chosen once, the first time no scope holds one: someone who used the
+   * editor before presets (a saved layout, or other recent projects) keeps every panel, anyone
+   * else starts simple. Writing it also for a new user keeps their first saved layout from making
+   * them look like an existing one on the next load.
+   */
+  let preset = settings.get(CoreSettings.layoutPreset);
+  if (settings.inspect(CoreSettings.layoutPreset).effectiveScope === 'default') {
+    preset = !layout.firstRun || options.knownUser ? 'full' : 'simple';
+    void settings.set(CoreSettings.layoutPreset, preset, presetScope()).catch(() => undefined);
+    if (layout.firstRun && preset === 'full') void layout.reset('full');
+  }
+
+  /** Said once per browser: the default layout is composed again until something is saved. */
+  const NOTICE_KEY = 'nanoforge.layout.simpleNoticeShown';
+  const noticeShown = () => {
+    try {
+      return localStorage.getItem(NOTICE_KEY) !== null;
+    } catch {
+      return true;
+    }
+  };
+  if (layout.firstRun && preset === 'simple' && !noticeShown()) {
+    try {
+      localStorage.setItem(NOTICE_KEY, '1');
+    } catch {}
+    shell.notifications.notify('info', 'Only the main panels are shown', {
+      detail: 'View › Panels opens the others, or show them all.',
+      actions: [{ title: 'Show all panels', run: () => usePreset('full') }],
+    });
+  }
 
   const dynamic = store.add(new DisposableStore());
   const refreshMenus = () => {
@@ -135,6 +187,8 @@ export const setupWorkbench = (options: WorkbenchSetupOptions): WorkbenchContext
     }
     add({ menu: 'view.layouts', command: 'layout.saveAs', group: 'manage', order: 0 });
     add({ menu: 'view.layouts', command: 'layout.reset', group: 'manage', order: 1 });
+    add({ menu: 'view.layouts', command: 'layout.simple', group: 'presets', order: 0 });
+    add({ menu: 'view.layouts', command: 'layout.full', group: 'presets', order: 1 });
     for (const name of layout.savedNames) {
       add({
         menu: 'view.layouts',
diff --git a/packages/ui/test/workbench/notification/describe-error.spec.ts b/packages/ui/test/workbench/notification/describe-error.spec.ts
new file mode 100644
index 00000000..a115eac5
--- /dev/null
+++ b/packages/ui/test/workbench/notification/describe-error.spec.ts
@@ -0,0 +1,74 @@
+import { describe, expect, it } from 'vitest';
+
+import { describeError, notifyError } from '../../../src/workbench/notification/describe-error';
+import { NotificationService } from '../../../src/workbench/notification/notification-service';
+
+const rpcError = (code: string, message: string) => Object.assign(new Error(message), { code });
+
+describe('describeError', () => {
+  it('says known errors in plain words and keeps the raw message', () => {
+    const away = describeError(rpcError('UNAVAILABLE', 'Editor server unreachable: fetch failed'));
+    expect(away.hint).toMatch(/can't be reached/);
+    expect(away.technical).toBe('Editor server unreachable: fetch failed');
+    expect(describeError(rpcError('UNAVAILABLE', 'fetch failed')).retryable).toBe(true);
+    expect(describeError(new Error('Something odd')).hint).toBeUndefined();
+  });
+
+  it("keeps the server's own words when they are already plain", () => {
+    const exists = describeError(rpcError('CONFLICT', 'Already exists: a.ts'));
+    expect(exists.hint).toBeUndefined();
+    expect(exists.retryable).toBe(false);
+    const notifications = new NotificationService();
+    notifyError(
+      notifications,
+      'The file operation failed',
+      rpcError('CONFLICT', 'Already exists: a.ts'),
+    );
+    expect(notifications.history.get()[0]).toMatchObject({ detail: 'Already exists: a.ts' });
+  });
+});
+
+describe('notifyError', () => {
+  it('offers Try again only when it may work, and the raw message behind details', () => {
+    const notifications = new NotificationService();
+    const retry = () => undefined;
+    notifyError(notifications, 'Could not save a.ts', rpcError('UNAVAILABLE', 'fetch failed'), {
+      retry,
+    });
+    notifyError(notifications, 'Could not save a.ts', rpcError('FORBIDDEN', 'Permission denied'), {
+      retry,
+    });
+    notifyError(notifications, 'Could not read b.ts', new Error('Unexpected token'));
+    const [away, conflict, plain] = notifications.history.get().toReversed();
+    expect(away).toMatchObject({ technical: 'fetch failed', actions: [{ title: 'Try again' }] });
+    expect(conflict!.actions).toEqual([]);
+    expect(plain).toMatchObject({ detail: 'Unexpected token' });
+    expect(plain!.technical).toBeUndefined();
+  });
+});
+
+describe('describeError for git and the server', () => {
+  it("shows git's own message on a failed command, the hint only for the server's generic one", () => {
+    const rejected = describeError(rpcError('INTERNAL', '! [rejected] main -> main (fetch first)'));
+    expect(rejected.hint).toBeUndefined();
+    expect(rejected.technical).toBe('! [rejected] main -> main (fetch first)');
+    expect(rejected.retryable).toBe(false);
+    expect(describeError(rpcError('INTERNAL', 'Internal error')).hint).toMatch(
+      /Something went wrong in the editor server/,
+    );
+  });
+
+  it('keeps the message of a timeout and offers to try again', () => {
+    const message = 'git push got no answer from the remote: run it once in a terminal';
+    const stuck = describeError(rpcError('TIMEOUT', message));
+    expect(stuck).toMatchObject({ hint: undefined, technical: message, retryable: true });
+    const notifications = new NotificationService();
+    notifyError(notifications, 'Push failed', rpcError('TIMEOUT', message), {
+      retry: () => undefined,
+    });
+    expect(notifications.history.get()[0]).toMatchObject({
+      detail: message,
+      actions: [{ title: 'Try again' }],
+    });
+  });
+});
diff --git a/packages/ui/test/workbench/setup/setup-workbench.spec.ts b/packages/ui/test/workbench/setup/setup-workbench.spec.ts
new file mode 100644
index 00000000..621dd89c
--- /dev/null
+++ b/packages/ui/test/workbench/setup/setup-workbench.spec.ts
@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+
+import { HistoryService } from '@nanoforge-dev/editor-history';
+import {
+  CommandRegistry,
+  Container,
+  ContextKeyService,
+  ExtensionRegistry,
+} from '@nanoforge-dev/editor-kernel';
+import { emptyLayout } from '@nanoforge-dev/editor-layout';
+import {
+  CoreSettings,
+  MemoryScopeStore,
+  SettingsRegistry,
+  SettingsService,
+} from '@nanoforge-dev/editor-settings';
+
+import { NotificationService } from '../../../src/workbench/notification/notification-service';
+import { setupWorkbench } from '../../../src/workbench/setup/setup-workbench';
+
+const settingsWith = async (stores: { account?: MemoryScopeStore; machine?: MemoryScopeStore }) => {
+  const registry = new SettingsRegistry();
+  registry.register(...Object.values(CoreSettings));
+  const settings = new SettingsService(registry);
+  const projectLocal = new MemoryScopeStore();
+  await settings.setStore('projectLocal', projectLocal);
+  for (const [scope, store] of Object.entries(stores))
+    await settings.setStore(scope as 'account' | 'machine', store);
+  return { settings, projectLocal };
+};
+
+const open = (settings: SettingsService, knownUser?: boolean) => {
+  const contextKeys = new ContextKeyService();
+  return setupWorkbench({
+    shell: { notifications: new NotificationService(), styles: {}, prompts: {} } as never,
+    services: {} as never,
+    extensions: new ExtensionRegistry(),
+    commands: new CommandRegistry(new Container(), contextKeys),
+    contextKeys,
+    settings,
+    history: new HistoryService(),
+    logger: { warn: () => undefined, error: () => undefined } as never,
+    activate: async () => undefined,
+    ...(knownUser !== undefined && { knownUser }),
+  });
+};
+
+const preset = (store: MemoryScopeStore) => store.values.get()[CoreSettings.layoutPreset.key];
+
+describe('setupWorkbench default layout', () => {
+  it('keeps every panel for someone with a saved layout and no default chosen', async () => {
+    const account = new MemoryScopeStore();
+    const { settings } = await settingsWith({ account });
+    await settings.set(CoreSettings.layoutSaved, { default: emptyLayout() }, 'projectLocal');
+    const workbench = open(settings);
+    expect(workbench.layout.firstRun).toBe(false);
+    await expect.poll(() => preset(account)).toBe('full');
+    workbench.dispose();
+  });
+
+  it('starts a new user with the main panels and writes it', async () => {
+    const account = new MemoryScopeStore();
+    const { settings } = await settingsWith({ account });
+    const workbench = open(settings);
+    expect(workbench.layout.firstRun).toBe(true);
+    await expect.poll(() => preset(account)).toBe('simple');
+    workbench.dispose();
+  });
+
+  it('keeps a new user on the main panels once their layout is saved', async () => {
+    const account = new MemoryScopeStore();
+    const { settings, projectLocal } = await settingsWith({ account });
+    const first = open(settings);
+    await expect.poll(() => preset(account)).toBe('simple');
+    await first.layout.apply({ type: 'resizeSlot', slot: 'bottom', size: 320 });
+    first.dispose();
+    await expect.poll(() => projectLocal.values.get()[CoreSettings.layoutSaved.key]).toBeDefined();
+
+    const second = open(settings);
+    expect(second.layout.firstRun).toBe(false);
+    await Promise.resolve();
+    expect(preset(account)).toBe('simple');
+    expect(settings.get(CoreSettings.layoutPreset)).toBe('simple');
+    second.dispose();
+  });
+
+  it('keeps every panel for someone who worked in other projects', async () => {
+    const account = new MemoryScopeStore();
+    const { settings } = await settingsWith({ account });
+    const workbench = open(settings, true);
+    await expect.poll(() => preset(account)).toBe('full');
+    workbench.dispose();
+  });
+
+  it('switches the default layout in the scope that holds it', async () => {
+    const account = new MemoryScopeStore();
+    const machine = new MemoryScopeStore({ [CoreSettings.layoutPreset.key]: 'full' });
+    const { settings } = await settingsWith({ account, machine });
+    const workbench = open(settings);
+    await workbench.commands.execute('layout.simple');
+    expect(preset(machine)).toBe('simple');
+    expect(preset(account)).toBeUndefined();
+    expect(settings.get(CoreSettings.layoutPreset)).toBe('simple');
+    workbench.dispose();
+  });
+});
diff --git a/plugins/code-editor/nanoforge.manifest.json b/plugins/code-editor/nanoforge.manifest.json
index 32e8a24c..1b8e4e8c 100644
--- a/plugins/code-editor/nanoforge.manifest.json
+++ b/plugins/code-editor/nanoforge.manifest.json
@@ -17,6 +17,7 @@
     "widgets": [
       {
         "id": "code-editor.script",
+        "description": "The code of your game: components, systems, scenes.",
         "title": "Script",
         "icon": "code",
         "kind": "screen",
diff --git a/plugins/code-editor/src/document/editor-document.ts b/plugins/code-editor/src/document/editor-document.ts
index 2a845ffe..ff47d361 100644
--- a/plugins/code-editor/src/document/editor-document.ts
+++ b/plugins/code-editor/src/document/editor-document.ts
@@ -7,6 +7,7 @@ import {
   ObservableValue,
   type OpenDocument,
   type TextEdit,
+  errorCodeOf,
 } from '@nanoforge-dev/editor-sdk';
 
 import { type Monaco, type monaco, uriOf } from '../monaco/monaco';
@@ -22,8 +23,7 @@ const modelFor = (monaco: Monaco, path: string, text: string): monaco.editor.ITe
   return existing;
 };
 
-const isConflict = (error: unknown): boolean =>
-  typeof error === 'object' && error !== null && (error as { code?: unknown }).code === 'CONFLICT';
+const isConflict = (error: unknown): boolean => errorCodeOf(error) === 'CONFLICT';
 
 /**
  * A file open in the code editor: a Monaco model, registered with the DocumentService so edits
diff --git a/plugins/code-editor/src/index.ts b/plugins/code-editor/src/index.ts
index 4aa29e75..12e4e717 100644
--- a/plugins/code-editor/src/index.ts
+++ b/plugins/code-editor/src/index.ts
@@ -79,6 +79,11 @@ export default definePlugin({
         settings: services.get(SettingsServiceToken),
         notifications: services.tryGet(NotificationServiceToken),
         logger: context.logger,
+        runCommand: (id) =>
+          void services
+            .get(EditorServices.Commands)
+            .execute(id)
+            .catch(() => undefined),
       });
       service.applyTheme(themes.current.get());
       current.set({ service, monaco });
diff --git a/plugins/code-editor/src/service/code-editor-service.ts b/plugins/code-editor/src/service/code-editor-service.ts
index 744666ca..c2375819 100644
--- a/plugins/code-editor/src/service/code-editor-service.ts
+++ b/plugins/code-editor/src/service/code-editor-service.ts
@@ -6,7 +6,7 @@ import {
   type Observable,
   ObservableValue,
 } from '@nanoforge-dev/editor-sdk';
-import type { ThemeDefinition } from '@nanoforge-dev/editor-sdk/ui';
+import { type ThemeDefinition, notifyError } from '@nanoforge-dev/editor-sdk/ui';
 
 import { EditorDocument } from '../document/editor-document';
 import { createUnsavedStore } from '../document/unsaved-store';
@@ -297,6 +297,11 @@ export class CodeEditorService implements Disposable {
     this._options.monaco.editor.setTheme('nanoforge');
   }
 
+  /** Runs an editor command, when the editor gave a way to. */
+  runCommand(id: string): void {
+    this._options.runCommand?.(id);
+  }
+
   dispose(): void {
     for (const timer of this._autoSaveTimers.values()) clearTimeout(timer);
     for (const path of [...this._documents.keys()]) this._release(path);
@@ -463,8 +468,6 @@ export class CodeEditorService implements Disposable {
 
   private _report(title: string, error: unknown): void {
     this._options.logger.warn(title, error);
-    this._options.notifications?.notify('error', title, {
-      detail: error instanceof Error ? error.message : String(error),
-    });
+    notifyError(this._options.notifications, title, error);
   }
 }
diff --git a/plugins/code-editor/src/service/code-editor.type.ts b/plugins/code-editor/src/service/code-editor.type.ts
index 1e6c4b44..283d0220 100644
--- a/plugins/code-editor/src/service/code-editor.type.ts
+++ b/plugins/code-editor/src/service/code-editor.type.ts
@@ -50,4 +50,6 @@ export interface CodeEditorServiceOptions {
   readonly settings: SettingsService;
   readonly notifications: NotificationService | undefined;
   readonly logger: Logger;
+  /** Runs an editor command (the empty screen offers Go to file). */
+  readonly runCommand?: (id: string) => void;
 }
diff --git a/plugins/code-editor/src/widgets/script/EditorGroupView.svelte b/plugins/code-editor/src/widgets/script/EditorGroupView.svelte
index 22a4ab8f..948d459b 100644
--- a/plugins/code-editor/src/widgets/script/EditorGroupView.svelte
+++ b/plugins/code-editor/src/widgets/script/EditorGroupView.svelte
@@ -289,8 +289,14 @@
       <EmptyState
         icon="file-code"
         title="No file open"
-        description="Open a file from the Files panel, or with Go to definition."
-      />
+        description="Open a file from the Files panel, or find one by name."
+      >
+        {#snippet actions()}
+          <Button icon="search" onclick={() => service.runCommand('palette.files')}
+            >Go to file…</Button
+          >
+        {/snippet}
+      </EmptyState>
     {/if}
   </div>
 </section>
diff --git a/plugins/console/nanoforge.manifest.json b/plugins/console/nanoforge.manifest.json
index 297097b2..88cb0fba 100644
--- a/plugins/console/nanoforge.manifest.json
+++ b/plugins/console/nanoforge.manifest.json
@@ -12,6 +12,7 @@
     "widgets": [
       {
         "id": "console.console",
+        "essential": true,
         "title": "Console",
         "icon": "square-terminal",
         "defaultSlot": "bottom",
diff --git a/plugins/ecs/nanoforge.manifest.json b/plugins/ecs/nanoforge.manifest.json
index 4e8018cd..d3657903 100644
--- a/plugins/ecs/nanoforge.manifest.json
+++ b/plugins/ecs/nanoforge.manifest.json
@@ -38,6 +38,7 @@
     "widgets": [
       {
         "id": "ecs.hierarchy",
+        "essential": true,
         "title": "Hierarchy",
         "icon": "list-tree",
         "defaultSlot": "leftTop",
@@ -45,6 +46,7 @@
       },
       {
         "id": "ecs.inspector",
+        "essential": true,
         "title": "Inspector",
         "icon": "sliders-horizontal",
         "defaultSlot": "rightTop",
diff --git a/plugins/ecs/src/library/create-shared-library.ts b/plugins/ecs/src/library/create-shared-library.ts
index 71f9d8ed..23b68d93 100644
--- a/plugins/ecs/src/library/create-shared-library.ts
+++ b/plugins/ecs/src/library/create-shared-library.ts
@@ -6,7 +6,7 @@ import {
   runnableApps,
   workspaceIo,
 } from '@nanoforge-dev/editor-sdk';
-import { NotificationServiceToken } from '@nanoforge-dev/editor-sdk/ui';
+import { NotificationServiceToken, notifyError } from '@nanoforge-dev/editor-sdk/ui';
 
 import { refactorsHistory } from './refactors-history';
 
@@ -36,11 +36,11 @@ export const createSharedLibrary = async (
     await refactorsHistory(context).push(command);
     return true;
   } catch (error) {
-    context.services
-      .tryGet(NotificationServiceToken)
-      ?.notify('error', 'Could not create the shared library', {
-        detail: error instanceof Error ? error.message : String(error),
-      });
+    notifyError(
+      context.services.tryGet(NotificationServiceToken),
+      'Could not create the shared library',
+      error,
+    );
     return false;
   }
 };
diff --git a/plugins/ecs/src/widgets/browser/create-flows.ts b/plugins/ecs/src/widgets/browser/create-flows.ts
index d24bcb4a..63554912 100644
--- a/plugins/ecs/src/widgets/browser/create-flows.ts
+++ b/plugins/ecs/src/widgets/browser/create-flows.ts
@@ -4,7 +4,11 @@ import {
   validateFolder,
   validatePackageName,
 } from '@nanoforge-dev/editor-sdk';
-import type { NotificationService, PromptService } from '@nanoforge-dev/editor-sdk/ui';
+import {
+  type NotificationService,
+  type PromptService,
+  notifyError,
+} from '@nanoforge-dev/editor-sdk/ui';
 
 import { type ItemKind, createItem, validateItemName } from '../../create/create-item';
 import type { EcsService } from '../../service/ecs-service';
@@ -36,9 +40,7 @@ export const createItemFlow = async (
     const path = await createItem(project, kind, name, target);
     await ecs.openInCode(path);
   } catch (error) {
-    notifications?.notify('error', `Could not create ${name}`, {
-      detail: error instanceof Error ? error.message : String(error),
-    });
+    notifyError(notifications, `Could not create ${name}`, error);
   }
 };
 
diff --git a/plugins/file-manager/nanoforge.manifest.json b/plugins/file-manager/nanoforge.manifest.json
index 8aeaccd4..36d3450d 100644
--- a/plugins/file-manager/nanoforge.manifest.json
+++ b/plugins/file-manager/nanoforge.manifest.json
@@ -20,6 +20,7 @@
     "widgets": [
       {
         "id": "file-manager.files",
+        "essential": true,
         "title": "Files",
         "icon": "folder-tree",
         "defaultSlot": "leftTop",
diff --git a/plugins/file-manager/src/service/file-manager-service.ts b/plugins/file-manager/src/service/file-manager-service.ts
index 7082ca6e..59b62d42 100644
--- a/plugins/file-manager/src/service/file-manager-service.ts
+++ b/plugins/file-manager/src/service/file-manager-service.ts
@@ -10,7 +10,12 @@ import {
   editorsFor,
   matchesGlob,
 } from '@nanoforge-dev/editor-sdk';
-import { FILE_ICONS, FILE_TEMPLATES, type FileTemplate } from '@nanoforge-dev/editor-sdk/ui';
+import {
+  FILE_ICONS,
+  FILE_TEMPLATES,
+  type FileTemplate,
+  notifyError,
+} from '@nanoforge-dev/editor-sdk/ui';
 
 import { isPackagePath } from '../filter/file-filter';
 import type { Clipboard, FileManagerServiceOptions } from './file-manager-service.type';
@@ -303,7 +308,8 @@ export class FileManagerService implements Disposable {
       await task();
       return true;
     } catch (error) {
-      this._report(error instanceof Error ? error.message : String(error));
+      this._options.logger.warn('A file operation failed', error);
+      notifyError(this._options.notifications, 'The file operation failed', error);
       return false;
     }
   }
diff --git a/plugins/git/src/index.ts b/plugins/git/src/index.ts
index 28a634ee..e3b6351d 100644
--- a/plugins/git/src/index.ts
+++ b/plugins/git/src/index.ts
@@ -15,6 +15,7 @@ import {
   StyleServiceToken,
   WIDGET_VIEWS,
   type WidgetInstance,
+  notifyError,
   registerIcons,
 } from '@nanoforge-dev/editor-sdk/ui';
 
@@ -41,9 +42,7 @@ export default definePlugin({
     const projects = services.get(ProjectServiceToken);
     const contextKeys = services.get(EditorServices.ContextKeys);
     const store = new GitStore((title, error) =>
-      services.tryGet(NotificationServiceToken)?.notify('error', title, {
-        detail: error instanceof Error ? error.message : String(error),
-      }),
+      notifyError(services.tryGet(NotificationServiceToken), title, error),
     );
     context.subscriptions.add(store);
     const actions = createActions({
diff --git a/plugins/git/src/store/git-store.ts b/plugins/git/src/store/git-store.ts
index 3f601873..62bd2927 100644
--- a/plugins/git/src/store/git-store.ts
+++ b/plugins/git/src/store/git-store.ts
@@ -5,6 +5,7 @@ import {
   type GitStash,
   type GitStatus,
   ObservableValue,
+  errorCodeOf,
 } from '@nanoforge-dev/editor-sdk';
 
 /** The git API of one project (the RPC contract with the project bound). */
@@ -163,7 +164,7 @@ export class GitStore implements Disposable {
       });
     } catch (error) {
       if (generation !== this._generation) return;
-      if ((error as { code?: string }).code === 'FORBIDDEN') {
+      if (errorCodeOf(error) === 'FORBIDDEN') {
         this._patch({ ...EMPTY, unavailable: 'Git is available in local editors only.' });
         return;
       }
diff --git a/plugins/git/src/widgets/commit/ChangesTab.svelte b/plugins/git/src/widgets/commit/ChangesTab.svelte
index adb84e9e..f8402203 100644
--- a/plugins/git/src/widgets/commit/ChangesTab.svelte
+++ b/plugins/git/src/widgets/commit/ChangesTab.svelte
@@ -36,14 +36,14 @@
       ? [
           {
             id: 'conflicts',
-            title: 'Merge Conflicts',
+            title: 'Merge conflicts',
             rows: lists.conflicts,
             checkable: false,
           } as const,
         ]
       : []),
     { id: 'changes', title: 'Changes', rows: lists.changes, checkable: true },
-    { id: 'unversioned', title: 'Unversioned Files', rows: lists.unversioned, checkable: true },
+    { id: 'unversioned', title: 'Unversioned files', rows: lists.unversioned, checkable: true },
   ]);
   const busy = $derived($git.busy);
 
@@ -109,7 +109,7 @@
     {
       kind: 'item',
       id: 'diff',
-      label: 'Show Diff',
+      label: 'Show diff',
       shortcut: 'Ctrl+D',
       disabled: selectedRows.length !== 1,
       onSelect: () => selectedRows[0] && showDiff(selectedRows[0]),
@@ -117,7 +117,7 @@
     {
       kind: 'item',
       id: 'source',
-      label: 'Jump to Source',
+      label: 'Jump to source',
       shortcut: 'F4',
       disabled: selectedRows.length !== 1 || selectedRows[0]?.letter === 'D',
       onSelect: () => selectedRows[0] && jumpToSource(selectedRows[0]),
@@ -207,14 +207,14 @@
   <IconButton
     icon="file-diff"
     size={14}
-    label="Show Diff"
+    label="Show diff"
     disabled={selectedRows.length !== 1}
     onclick={() => selectedRows[0] && showDiff(selectedRows[0])}
   />
   <IconButton
     icon="archive"
     size={14}
-    label="Stash Changes"
+    label="Stash changes"
     disabled={busy || (!lists.changes.length && !lists.unversioned.length)}
     onclick={() => void act.stash()}
   />
@@ -222,13 +222,13 @@
   <IconButton
     icon="chevrons-up-down"
     size={14}
-    label="Expand All"
+    label="Expand all"
     onclick={() => (panel.folded = [])}
   />
   <IconButton
     icon="chevrons-down-up"
     size={14}
-    label="Collapse All"
+    label="Collapse all"
     onclick={() => (panel.folded = groups.map((group) => group.id))}
   />
 </div>
diff --git a/plugins/git/src/widgets/commit/CommitMessage.svelte b/plugins/git/src/widgets/commit/CommitMessage.svelte
index f588371c..e6f05a7f 100644
--- a/plugins/git/src/widgets/commit/CommitMessage.svelte
+++ b/plugins/git/src/widgets/commit/CommitMessage.svelte
@@ -74,7 +74,7 @@
     <span class="grow"></span>
     <Menu items={messageHistory} align="end">
       {#snippet trigger({ props })}
-        <IconButton {...props} icon="history" size={14} label="Commit Message History" />
+        <IconButton {...props} icon="history" size={14} label="Commit message history" />
       {/snippet}
     </Menu>
   </div>
@@ -95,7 +95,7 @@
       >Commit</Button
     >
     <Button size="sm" disabled={!canCommit} onclick={() => void commit(true)}
-      >Commit and Push…</Button
+      >Commit and push…</Button
     >
   </div>
 </div>
diff --git a/plugins/git/src/widgets/commit/StashTab.svelte b/plugins/git/src/widgets/commit/StashTab.svelte
index deff87ea..f207a83e 100644
--- a/plugins/git/src/widgets/commit/StashTab.svelte
+++ b/plugins/git/src/widgets/commit/StashTab.svelte
@@ -21,7 +21,7 @@
     size="sm"
     variant="ghost"
     disabled={$git.busy || !hasChanges}
-    onclick={() => void act.stash()}>Stash Changes</Button
+    onclick={() => void act.stash()}>Stash changes</Button
   >
 </div>
 <ul class="scroll" aria-label="Stashes">
diff --git a/plugins/git/src/widgets/log/BranchTree.svelte b/plugins/git/src/widgets/log/BranchTree.svelte
index 4f59186c..258d3661 100644
--- a/plugins/git/src/widgets/log/BranchTree.svelte
+++ b/plugins/git/src/widgets/log/BranchTree.svelte
@@ -84,7 +84,7 @@
       {
         kind: 'item',
         id: 'new',
-        label: `New Branch from '${branch.name}'…`,
+        label: `New branch from '${branch.name}'…`,
         onSelect: () => void act.newBranch(branch.name),
       },
       { kind: 'separator' },
@@ -153,27 +153,27 @@
     <IconButton
       icon="plus"
       size={14}
-      label="New Branch"
+      label="New branch"
       onclick={() => void act.newBranch(selectedBranchEntry?.name)}
     />
     <IconButton
       icon="arrow-down-to-line"
       size={14}
-      label="Update Selected"
+      label="Update selected"
       disabled={busy}
       onclick={() => void act.pull()}
     />
     <IconButton
       icon="trash-2"
       size={14}
-      label="Delete Branch"
+      label="Delete branch"
       disabled={!selectedBranchEntry || selectedBranchEntry.current || selectedBranchEntry.remote}
       onclick={() => selectedBranchEntry && remove(selectedBranchEntry)}
     />
     <IconButton
       icon="refresh-cw"
       size={14}
-      label="Fetch All Remotes"
+      label="Fetch all remotes"
       disabled={busy}
       onclick={() => void act.fetch()}
     />
diff --git a/plugins/git/src/widgets/log/CommitTable.svelte b/plugins/git/src/widgets/log/CommitTable.svelte
index 0decdd73..485b5d12 100644
--- a/plugins/git/src/widgets/log/CommitTable.svelte
+++ b/plugins/git/src/widgets/log/CommitTable.svelte
@@ -59,13 +59,13 @@
       {
         kind: 'item',
         id: 'copy',
-        label: 'Copy Revision Number',
+        label: 'Copy revision number',
         onSelect: () => void navigator.clipboard?.writeText(commit.hash).catch(() => undefined),
       },
       {
         kind: 'item',
         id: 'branch',
-        label: 'New Branch…',
+        label: 'New branch…',
         onSelect: () => void act.newBranch(commit.hash),
       },
     ];
diff --git a/plugins/history-panel/nanoforge.manifest.json b/plugins/history-panel/nanoforge.manifest.json
index 7113e4c2..bb46efad 100644
--- a/plugins/history-panel/nanoforge.manifest.json
+++ b/plugins/history-panel/nanoforge.manifest.json
@@ -12,6 +12,7 @@
     "widgets": [
       {
         "id": "history-panel.history",
+        "openByDefault": false,
         "title": "History",
         "icon": "history",
         "defaultSlot": "rightTop",
diff --git a/plugins/packages/src/dialogs/packages/packages-dialog-state.svelte.ts b/plugins/packages/src/dialogs/packages/packages-dialog-state.svelte.ts
index 31df34bb..96535628 100644
--- a/plugins/packages/src/dialogs/packages/packages-dialog-state.svelte.ts
+++ b/plugins/packages/src/dialogs/packages/packages-dialog-state.svelte.ts
@@ -4,6 +4,7 @@ import {
   type RegistryItem,
   type RegistrySummary,
   type RpcClient,
+  errorCodeOf,
 } from '@nanoforge-dev/editor-sdk';
 
 import { missing } from '../../model/installed-package';
@@ -12,7 +13,6 @@ export const registryApi = (rpc: RpcClient) => rpc.api(RegistryContract);
 export type RegistryApi = ReturnType<typeof registryApi>;
 
 const message = (error: unknown) => (error instanceof Error ? error.message : String(error));
-const codeOf = (error: unknown) => (error as { code?: string }).code;
 
 /**
  * What the Packages dialog keeps while its tabs come and go: the search, the selected package,
@@ -55,7 +55,7 @@ export class PackagesDialogState {
       this.installed = await this._registry.packages({ project: this.project });
       this.readOnly = undefined;
     } catch (error) {
-      if (codeOf(error) === 'FORBIDDEN')
+      if (errorCodeOf(error) === 'FORBIDDEN')
         this.readOnly = 'Packages can only be installed in a local editor.';
       else this.failure = message(error);
     }
@@ -77,7 +77,7 @@ export class PackagesDialogState {
       this.results = [];
       this.total = 0;
       this.unavailable =
-        codeOf(error) === 'UNAVAILABLE'
+        errorCodeOf(error) === 'UNAVAILABLE'
           ? 'The package registry cannot be reached right now. Installed packages keep working.'
           : message(error);
     } finally {
@@ -136,7 +136,7 @@ export class PackagesDialogState {
       void this._catalog?.refresh();
     } catch (error) {
       this.failure =
-        codeOf(error) === 'FORBIDDEN'
+        errorCodeOf(error) === 'FORBIDDEN'
           ? 'Packages can only be installed in a local editor.'
           : message(error);
     } finally {
diff --git a/plugins/scene/nanoforge.manifest.json b/plugins/scene/nanoforge.manifest.json
index ca054a61..c62c4f27 100644
--- a/plugins/scene/nanoforge.manifest.json
+++ b/plugins/scene/nanoforge.manifest.json
@@ -30,6 +30,7 @@
     "widgets": [
       {
         "id": "scene.scenes",
+        "essential": true,
         "title": "Scenes",
         "icon": "layers",
         "defaultSlot": "leftTop",
diff --git a/plugins/settings-ui/src/dialogs/settings/plugins/plugins-page-state.svelte.ts b/plugins/settings-ui/src/dialogs/settings/plugins/plugins-page-state.svelte.ts
index af8e49c3..3a3d374a 100644
--- a/plugins/settings-ui/src/dialogs/settings/plugins/plugins-page-state.svelte.ts
+++ b/plugins/settings-ui/src/dialogs/settings/plugins/plugins-page-state.svelte.ts
@@ -7,6 +7,7 @@ import {
   type RegistrySummary,
   type RpcClient,
   type SettingsService,
+  errorCodeOf,
 } from '@nanoforge-dev/editor-sdk';
 
 import {
@@ -26,7 +27,6 @@ export type RegistryApi = ReturnType<typeof registryApi>;
 export type PluginDetails = RegistryItem & { compatible?: string | undefined };
 
 const message = (error: unknown) => (error instanceof Error ? error.message : String(error));
-const codeOf = (error: unknown) => (error as { code?: string }).code;
 
 /**
  * What the Plugins page keeps while its tabs come and go: the marketplace search, the selected
@@ -82,7 +82,7 @@ export class PluginsPageState {
       this.results = [];
       this.total = 0;
       this.unavailable =
-        codeOf(error) === 'UNAVAILABLE'
+        errorCodeOf(error) === 'UNAVAILABLE'
           ? 'The plugin registry cannot be reached right now. Installed plugins keep working.'
           : message(error);
     } finally {
@@ -148,7 +148,7 @@ export class PluginsPageState {
       this.pending.set(name, await action());
     } catch (error) {
       this.failure =
-        codeOf(error) === 'FORBIDDEN'
+        errorCodeOf(error) === 'FORBIDDEN'
           ? 'Plugins can only be installed in a local editor.'
           : `${name}: ${message(error)}`;
     } finally {
diff --git a/plugins/viewport/nanoforge.manifest.json b/plugins/viewport/nanoforge.manifest.json
index 8fa067b1..99e9d8e4 100644
--- a/plugins/viewport/nanoforge.manifest.json
+++ b/plugins/viewport/nanoforge.manifest.json
@@ -16,6 +16,7 @@
     "widgets": [
       {
         "id": "viewport.scene",
+        "description": "Your entities drawn in 2D: select and move them.",
         "title": "Scene",
         "icon": "box",
         "kind": "screen",
@@ -23,6 +24,7 @@
       },
       {
         "id": "viewport.game",
+        "description": "Play the game here, and see it run.",
         "title": "Game",
         "icon": "gamepad-2",
         "kind": "screen",