fix: let long page titles wrap in the page editor

[charan-rathore]

Fixes #68

What changed

The page title in the page editor was a single-line <input>, so a long title was cut off at the right edge. It is now an auto-growing <textarea> (PageTitleField) that wraps and resizes to its content. Same class name, aria-label, placeholder and 160 character limit as before.

Enter is ignored and pasted line breaks are turned into spaces, so a title stays a single logical line like it was with the input.

Tests

• Added tests/page-title-field.test.tsx: the field renders as a one-row textarea with the same label and limit, and line breaks are collapsed.
• npx vitest run: 36 files, 166 tests pass (current main c2569bb).
• npx tsc --noEmit, eslint on the changed files and prettier --check on the changed files are clean.

Not run

I did not run the production build or look at the page in a browser, so the wrapping and auto-resize are checked by code and the render test only. Narrow-screen layout is not visually checked.

[jerelvelarde]

Wrapping page titles fits the template and preserves its accessible label and 160-character limit, but hold merge because resizing clips the title again. Validation: 166 full tests, typecheck, lint, formatting, and production build passed; 8 focused title/autosave tests passed. Chromium used the actual component and styles. No apparent security expansion.

[jerelvelarde]

[P2] Recalculate title height when available width changes. This effect depends only on value. Resizing the actual field from 1440px to 375px leaves clientHeight at 208px while scrollHeight grows to 250px; overflow:hidden clips the last line until the user edits the title. Recalculate on element width changes, covering viewport and panel resizing, and add a browser regression for this case.