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>

core/site_manager.py

@@ -50,6 +50,7 @@ class SiteConfig(BaseModel):
     site_id: str = Field(..., description="Unique site identifier")
     plugin_type: str = Field(..., description="Plugin type (wordpress, gitea, etc)")
     alias: str | None = Field(None, description="Friendly alias for the site")
+    user_id: str | None = Field(None, description="Owner user ID for the site")
 
     # Common config fields (plugins may require additional fields)
     url: str | None = Field(None, description="Site URL")
@@ -452,6 +453,7 @@ class SiteManager:
                         "site_id": config.site_id,
                         "alias": config.alias,
                         "full_id": config.get_full_id(),
+                        "user_id": config.user_id,
                     }
                 )