Add local-first SPA architecture and containerized production deploy.

Move data access to use-cases and IndexedDB repositories with optional
remote fallback, changelog/sync ports, and encrypted local backup.
Add production Docker Compose (nginx frontend + optional backend) and
Apache host proxy configuration for deployment.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/infrastructure/sync/syncAdapter.js

@@ -0,0 +1,8 @@
+import { noopSyncAdapter } from './noopSyncAdapter'
+
+/**
+ * @returns {{pushChanges: Function, pullChanges: Function, ack: Function}}
+ */
+export function getSyncAdapter() {
+  return noopSyncAdapter
+}