Replace editor view polling with callbacks

[ComputelessComputer]

Expose NoteEditor view lifecycle callbacks and use them in NoteInput instead of polling the editor ref after render.

---

Note

Low Risk
Localized editor lifecycle wiring for UI caret behavior; no auth, persistence, or API changes.

Overview
Replaces per-render polling of internalEditorRef.current?.view in session NoteInput with explicit ProseMirror view lifecycle hooks, so caret-near-bottom tracking gets a stable EditorView when the editor mounts and clears it on teardown (e.g. raw ↔ enhanced tab switches).

NoteEditor gains optional onViewReady / onViewDisposed props. ViewCapture now runs disposal in the useEditorEffect cleanup (with a ref for latest callbacks) and still invokes the internal ready path that seeds debounced onUpdate before forwarding onViewReady. Raw, Enhanced, and EnhancedEditor pass these callbacks through unchanged.

NoteInput wires handleViewReady / handleViewDisposed into both tab editors; dispose only nulls state when the disposed view matches the current one, avoiding races if a new view is already active.

^{Reviewed by Cursor Bugbot for commit 791c919. Bugbot is set up for automated code reviews on this repo. Configure here.}

[netlify]

✅ Deploy Preview for old-char canceled.

Name	Link
🔨 Latest commit	791c919
🔍 Latest deploy log	https://app.netlify.com/projects/old-char/deploys/6a2bbe2ba3c4f8000735f823