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/path-browserify/security.md

@@ -0,0 +1,10 @@
+# Security Policy
+
+## Supported Versions
+Only the latest major version is supported at any given time.
+
+## Reporting a Vulnerability
+
+To report a security vulnerability, please use the
+[Tidelift security contact](https://tidelift.com/security).
+Tidelift will coordinate the fix and disclosure.