feat(app): add Electron desktop UI and evolve memory/retrieval layer

Introduce an Electron app with session browser, memory list, and usage
  views (vanilla JS + Vue scaffolding). On the data layer: add content_type
  and is_meta to messages for transcript control-plane filtering, introduce
  FTS5-backed memory recall with safe tokenization, support memory archival
  via forget() through the renamed --attune runtime, and expose anchors on
  memory records.

.gitignore

@@ -2,3 +2,4 @@
 plans/
 .skillopt-backups
 tests/
+node_modules/