feat: add Docker Compose profiles and Login Flow v2 service

Add selective service startup via Docker Compose profiles so each MCP
deployment mode runs independently. Also add the new mcp-login-flow
service (port 8004) for Login Flow v2 authentication (ADR-022).

Profile assignments:
- single-user: mcp (port 8000)
- multi-user-basic: mcp-multi-user-basic (port 8003)
- oauth: mcp-oauth (port 8001)
- keycloak: keycloak + mcp-keycloak (port 8002)
- login-flow: mcp-login-flow (port 8004)

Infrastructure services (db, redis, app, recipes) always start.

Integration tests cover the full Login Flow v2 provisioning flow:
OAuth → browser login → app password → Nextcloud API access for
notes, calendar, contacts, files, deck, and cookbook operations.

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

nextcloud_mcp_server/api/passwords.py

@@ -288,10 +288,28 @@ async def provision_app_password(request: Request) -> JSONResponse:
             status_code=500,
         )
 
+    # Parse optional scopes and username from request body
+    scopes = None
+    nc_username = None
+    try:
+        body = await request.json()
+        scopes = body.get("scopes")  # list[str] | None
+        nc_username = body.get("username")  # Nextcloud loginName
+    except Exception:
+        pass  # No JSON body = legacy call without scopes
+
     # Store the validated app password
     try:
         storage = await _get_app_password_storage(request)
-        await storage.store_app_password(username, app_password)
+
+        if scopes is not None or nc_username is not None:
+            # New path: store with scopes and username
+            await storage.store_app_password_with_scopes(
+                username, app_password, scopes=scopes, username=nc_username
+            )
+        else:
+            # Legacy path: store without scopes
+            await storage.store_app_password(username, app_password)
 
         _record_rate_limit_attempt(path_user_id, success=True)
         logger.info(f"Provisioned app password for user: {username}")
@@ -300,6 +318,7 @@ async def provision_app_password(request: Request) -> JSONResponse:
             {
                 "success": True,
                 "message": f"App password stored for {username}",
+                "scopes": scopes,
             }
         )