[roboclaw-bot]

What Problem This Solves

Documentation diagrams ship Mermaid and redraw on theme changes; the initial Pele candidate can measure labels before its webfonts are ready.

User Impact

Mermaid fences and component blocks render through Pele with the docs font faces and a 16px base size (14px sequence messages). Source exports, accessible descriptions, expansion, keyboard dismissal, navigation and strict diagram isolation remain intact. Layout follows Pele rather than Mermaid. No documentation content or deployment configuration changes are included.

Why This Change Was Made

Use one dependency-free renderer with CSS theme tokens instead of Mermaid initialization, chunk-copying and theme-rerender paths. Pin Pele 1.6.0, copy its complete license, and disable diagram-supplied links and images. Wait for body, bold and monospace label fonts before layout; failed font downloads retain normal browser fallback. Native font smoothing is unchanged. Requested by @vincentkoc.

Work sessions

• Original discussion with @vincentkoc
• Implementation and verification
• Initial implementation

Evidence

Follows merged #287. The cutover was reconciled onto its landed main commit without changes to renderer code, tests or dependencies. Local proof and screenshots retain their original executing revision; current-head CI is checked separately.

• Focused generated-page diagram, media-scene and analytics suites: 25/25 passed on this exact head. Chromium and WebKit cover cold-font geometry, hostile labels, unique accessible IDs, source/error preservation, dialog focus and horizontal reachability.
• The new cold-font regression fails on the original improve: render documentation diagrams with Pele #286 head: three diagrams are laid out while their fonts are deliberately held. It passes here, then checks geometry against a render with the loaded font.
• Bounded 30-page preview passed. Captured and inspected actual home and Gateway architecture pages in Chromium and WebKit, light/dark, 1440px/390px. Mobile expanded labels now stay at 16px for the home flowchart and 14px for sequence messages, instead of approximately 6–7px on the original improve: render documentation diagrams with Pele #286 head.
• Fresh independent Codex P0–P3 autoreview: scoped-clean. Syntax and whitespace checks passed.
• Prior corpus evidence retained: 175 source blocks, 163 unique, 162 render; the remaining malformed sequence is rejected by both renderers. The pinned parser is unchanged.

Split: stacked on #287, the independently useful three-file expansion repair. This PR keeps the dependency/lockfile, copied runtime, engine call, tokens and engine-specific checks in one atomic cutover; splitting those further would leave a broken build or temporarily ship two engines. Original #286, its head, body, credit and public evidence remain unchanged until the coordinating parent decides its disposition. No merge is performed here.

Verification limits: hosted checks are pending on these new heads. The prior full test run had seven head-drift mock failures reproduced on the unchanged base because of this host's native gh routing; it is not claimed green and that failing route was not rerun. Direct WebKit HTTP egress was previously refused, so fresh WebKit proof uses actual generated pages fulfilled from disk, not a direct HTTP server. The old #286 CI cancellation occurred during browser package installation before tests ran; no workflow timeout or dependency policy was relaxed.

Full-stack typography refinement on actual docs

Before is the original #286 head; after includes #287 plus this cutover. The expanded mobile view intentionally scrolls horizontally rather than reducing labels to a few pixels.

Before

After