fix(test): fix 17 pre-existing unit test failures and add astrolabe CI build

Unit test fixes:
- test_userinfo_routes: patch nextcloud_httpx_client instead of httpx.AsyncClient
- test_instrument_tool: patch trace_operation in metrics module (where imported)
- test_management_app_password_endpoints: patch nextcloud_httpx_client and
  get_settings at correct import locations
- test_management_status_endpoint: patch detect_auth_mode and get_settings at
  correct import locations (api.management, not config/config_validators)
- test_token_exchange: fix TokenBrokerService constructor args (client_id/
  client_secret instead of encryption_key)

CI:
- Add Node.js setup and astrolabe build step (composer + npm ci + npm run build)

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

pyproject.toml

@@ -64,7 +64,7 @@ Changelog = "https://github.com/cbcoutinho/nextcloud-mcp-server/blob/master/CHAN
 
 [tool.pytest.ini_options]
 anyio_mode = "auto"
-addopts = "--headed -p no:asyncio"  # Disable pytest-asyncio plugin, use only anyio
+addopts = "-p no:asyncio"  # Disable pytest-asyncio plugin, use only anyio
 log_cli = 1
 log_cli_level = "ERROR"
 log_level = "ERROR"