feat: v3.1.0 — Live Platform Foundation (Track E.1-E.3)

Major release introducing the Live Platform architecture:

- SQLite database backend with async operations and migrations (E.1)
- AES-256-GCM credential encryption with HKDF key derivation (E.1)
- OAuth Social Login with GitHub and Google (E.2)
- Site management API with encrypted credential storage (E.3)
- Per-user MCP endpoints at /u/{user_id}/{alias}/mcp (E.3)
- User API keys with bcrypt hashing (E.3)
- Auto-generated config snippets for 5 MCP clients (E.3)
- Dashboard: dark/light mode, RBAC, My Sites, Connect page
- Active background health checks
- 452 tests (up from 303), all passing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

requirements.txt

@@ -17,7 +17,13 @@ python-dotenv>=1.0.0
 # OAuth 2.1 Infrastructure
 authlib>=1.5.0          # OAuth 2.1 server/client implementation
 PyJWT>=2.8.0            # JWT encoding/decoding
-cryptography>=46.0.0    # For RSA/ECDSA JWT signing
+cryptography>=46.0.0    # For RSA/ECDSA JWT signing + AES-256-GCM encryption
 
-# Template engine for OAuth Authorization Page (Phase E)
+# Template engine for dashboard and OAuth pages
 jinja2>=3.1.2           # HTML template rendering
+
+# Database (Track E — Live Platform)
+aiosqlite>=0.20.0       # Async SQLite for user data, sites, API keys
+
+# User API key hashing (Track E.3)
+bcrypt>=4.0.0           # Secure password hashing for user API keys