Autosave edits and new pages as local drafts

[codeling]

Summary

Mobile browsers unload tabs that are left inactive, and any text in the edit field that hadn't been saved was lost. With this change, the edit form's content is kept as a draft in the browser's localStorage and restored when the page is opened again.

• The text, title and commit message are saved on every change and when the page gets hidden (visibilitychange / pagehide).
• When the edit or new page is opened again, the draft is restored and a note is shown. The note says when the draft was saved and has a Discard draft button.
• If the page was changed on the server after the draft was started, the note also shows a warning.
• The draft is removed on Save and on Cancel. It is also removed silently if it matches the server content.
• The draft key includes the script path and the page name (for new pages, the title the form opened with), so drafts for different pages and wiki instances stay separate.
• Nothing is written to the server until Save, so autosave creates no git commits.
• wiki.js and the Markdown formatting helper are now also loaded for new pages. Before, only edit pages loaded them, so new pages also get the "unsaved changes" warning when leaving.
• The new strings are added to the de and en locale files.

Testing

Checked in headless Chromium against php -S:

• An edit draft is restored after a reload.
• Discard draft brings back the original text and removes the draft.
• A new page's draft (title + text) is restored.
• Saving removes the draft.
• The conflict warning appears when the page was changed on disk after the draft was started.

🤖 Generated with Claude Code

https://claude.ai/code/session_01R83ERf8xo5QNNs6vp9v7at

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Generated by Claude Code