Complete Phase 2: Frontend implementation with React + TypeScript

Frontend Features:
- React 18 + Vite + TypeScript + Tailwind CSS + Zustand
- JWT authentication with automatic token refresh
- Tree library with search and category filtering
- Full tree navigation (decision/action/solution nodes)
- Session management with notes and completion
- Session history with export (Markdown/Text/HTML)
- ErrorBoundary for graceful error handling

Backend Fixes:
- CORS: Added port 5174 to allowed origins
- Sessions: Fixed JSONB datetime serialization (mode='json')

Documentation:
- Updated PROGRESS.md with Phase 2 completion
- Updated 03-DEVELOPMENT-ROADMAP.md with checked items
- Added PHASE-2.5-PERSONAL-BRANCHING.md spec

Seed Data:
- Added backend/scripts/seed_data.py with Password Reset tree

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "files": [],
+  "references": [
+    { "path": "./tsconfig.app.json" },
+    { "path": "./tsconfig.node.json" }
+  ]
+}