Add persistence and SQLite integration tests

docs/javascript-architecture.md

@@ -2090,6 +2090,21 @@ npm test
 - safe handling when no counted lap exists
 - competitor and judging-log filters
 
+`tests/runtime_persistence.test.js` covers:
+- persisted entity/settings normalization during backend hydration
+- invalid-theme fallback and retention of local setting defaults
+- hydration success/error behavior and no-write-back handling
+- full-state POST payloads and synced-version advancement
+- dirty-state protection when newer local edits occur during a request
+- failed-sync behavior without false version advancement
+
+`tests/server_persistence.integration.test.js` starts an isolated backend with a temporary SQLite data directory and covers:
+- health/database path reporting
+- empty-state response and full app-state round-trip
+- passing persistence and session-scoped passing queries
+- atomic hot-update of `resultsBySession[sessionId]` for overlay hydration
+- preservation of the rest of the stored state during a passing hot-update
+
 The suite uses Node's built-in `node:test` runner and does not add a test-framework dependency. Windows PowerShell/CMD can run the same suite with `npm.cmd test`.
 
 ## 19. Recommended Future Additions
@@ -2099,4 +2114,4 @@ If the project grows further, the next useful additions to this document are:
 - exact `settings` schema snapshot
 - SQLite table contract section
 - controller-to-view ID map for critical forms/buttons
-- additional test checklists for persistence modules
+- browser-level smoke tests for critical create/edit workflows