Sync offline cache on every page load, not just every 2 minutes

Online-side mutations (e.g. deleting a tag) only update the server, not
IndexedDB, so a throttled background sync could leave the offline cache
stale for up to two minutes. Going offline in that window resurrected
deleted/stale data (e.g. a deleted tag reappearing). Removing the throttle
so every real page load pulls fresh state keeps the offline cache in
sync with whatever was just done online.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

static/js/offline-sync.js

@@ -5,8 +5,6 @@
  * network-loaded page (never from the cached offline app).
  */
 
-const BACKGROUND_SYNC_MIN_INTERVAL_MS = 2 * 60 * 1000;
-
 // Bump this whenever a previously-untracked entity type starts being synced
 // (e.g. tags/time_entries were added after tasks-only syncing already
 // shipped). /api/sync/ only returns rows changed since a device's last sync
@@ -173,13 +171,3 @@ async function runBackgroundSync() {
     return hadPendingChanges || forceFullResync;
 }
 
-async function maybeBackgroundSync() {
-    const lastSyncAt = await getMeta('last_sync_at');
-    if (lastSyncAt && Date.now() - new Date(lastSyncAt).getTime() < BACKGROUND_SYNC_MIN_INTERVAL_MS) {
-        return;
-    }
-    const pushedChanges = await runBackgroundSync();
-    if (pushedChanges) {
-        window.location.reload();
-    }
-}