feat: icon-only toolbar, versioning fixes, history modal, PanelRight repositioning

- Toolbar: remove text labels from all icon buttons (AI, Save, Preview, Convert)
  all buttons now icon-only with title tooltip for accessibility
- Toolbar: reposition PanelRight (info panel toggle) to far right after three-dot menu
- Versioning: decouple getNoteHistory/restoreNoteVersion from global userAISettings.noteHistory
  now checks note.historyEnabled directly — unblocks manual per-note history
- Versioning: add 'Sauvegarder cette version' button in Versions tab of info panel
  calls commitNoteHistory with visual feedback (spinner → success state)
- note-document-info-panel: import commitNoteHistory, add isSavingVersion state
- notes.ts: fix double guard that silently blocked all history operations

architectural-grid (5)/README.md

@@ -0,0 +1,20 @@
+<div align="center">
+<img width="1200" height="475" alt="GHBanner" src="https://github.com/user-attachments/assets/0aa67016-6eaf-458a-adb2-6e31a0763ed6" />
+</div>
+
+# Run and deploy your AI Studio app
+
+This contains everything you need to run your app locally.
+
+View your app in AI Studio: https://ai.studio/apps/b7b577c6-4d9f-44ac-8fe1-85bc3c6d6e66
+
+## Run Locally
+
+**Prerequisites:**  Node.js
+
+
+1. Install dependencies:
+   `npm install`
+2. Set the `GEMINI_API_KEY` in [.env.local](.env.local) to your Gemini API key
+3. Run the app:
+   `npm run dev`