note palette: swatch previews body palette, NVM reverts, OK saves sitewide; note_set_palette also saves user.palette — TDD

- note-page.js: body class swap on swatch click; 10s auto-revert timer; NVM reverts;
  .note-item--active persists border/glow while modal open; .previewing on swatch
- billboard/views.py: note_set_palette also saves user.palette via _unlocked_palettes_for_user
- _note.scss: .note-swatch-body gradient (palette vars cascade from parent palette-* class);
  .previewing state; .note-item--active; note-palette-modal tooltip glass;
  note-palette-confirm floats below modal (position:absolute, out of flow)
- my_notes.html: note-item__body wrapper; image-box right; swatch row OK buttons removed
- FTs: T2a URL fix (/recognition → /my-notes); T2b split into preview+persist & NVM tests;
  NoteSetPaletteViewTest.test_also_saves_user_palette IT

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Sonnet 4.6 <noreply@anthropic.com>

src/static/tests/NoteSpec.js

@@ -88,9 +88,9 @@ describe('Note.showBanner', () => {
 
     // ── T7 ── NVM button ──────────────────────────────────────────────────────
 
-    it('T7: banner has a .btn.btn-danger NVM button', () => {
+    it('T7: banner has a .btn.btn-cancel NVM button', () => {
         Note.showBanner(SAMPLE_NOTE);
-        expect(document.querySelector('.note-banner .btn.btn-danger')).not.toBeNull();
+        expect(document.querySelector('.note-banner .btn.btn-cancel')).not.toBeNull();
     });
 
     // ── T8 ── FYI link ────────────────────────────────────────────────────────
@@ -106,7 +106,7 @@ describe('Note.showBanner', () => {
 
     it('T9: clicking the NVM button removes the banner from the DOM', () => {
         Note.showBanner(SAMPLE_NOTE);
-        document.querySelector('.note-banner .btn.btn-danger').click();
+        document.querySelector('.note-banner .btn.btn-cancel').click();
         expect(document.querySelector('.note-banner')).toBeNull();
     });