Dance library: bundled clips bind to any rigged model + repertoire + manual BPM

- models/dance_library.glb: skeleton-only GLB with the 13 Mixamo dances,
  loaded at startup and bound BY BONE NAME to whatever rigged GLB the
  user loads — new models dance immediately, no baking needed.
- Repertoire UI (Media tab): checkbox chips of the available clips, the
  director only picks the ticked ones (none = all); persisted.
- 'Aggiungi animazioni': extra .glb clips load directly; .fbx are
  converted on the fly by Blender via a new anim:convert IPC and the
  bundled scripts/fbx2animglb.py (asarUnpacked for packaged builds).
- Manual BPM with TAP tempo: 0 = follow the detected beat, otherwise a
  pure metronome drives the dance clock.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -27,7 +27,11 @@
       "preload.js",
       "src/**/*",
       "svg/**/*",
-      "models/**/*"
+      "models/**/*",
+      "scripts/fbx2animglb.py"
+    ],
+    "asarUnpack": [
+      "scripts/fbx2animglb.py"
     ]
   },
   "devDependencies": {