Phase 1 MVP - Complete implementation

- Login with JWT and refresh token rotation
- Dashboard with projects cards
- ProjectView with TreeView navigation
- DocumentView with markdown editor and auto-save
- Tag management (create, assign, remove)
- Dark mode CSS variables
- Security fixes applied (logout to backend, createDocument endpoint)

node_modules/source-map-js/lib/source-node.d.ts

@@ -0,0 +1 @@
+export { SourceNode } from '..';