Updates to add more ads and fix ad types.

lib/services/database_service.dart

@@ -65,7 +65,7 @@ class DatabaseService {
     final dbPath = p.join(_rootDirectory.path, dbFileName);
     _db = await openDatabase(
       dbPath,
-      version: 5,
+      version: 6,
       onCreate: _onCreate,
       onUpgrade: _onUpgrade,
     );
@@ -76,6 +76,7 @@ class DatabaseService {
     await db.execute(createFuelEntriesTableSql);
     await db.execute(createFuelEntriesIndexSql);
     await db.execute(createAdFreeEntitlementTableSql);
+    await db.execute(createAppUsageTableSql);
   }
 
   /// Versions 2/3 (VIN as primary key, then dropping license plate) were
@@ -94,6 +95,9 @@ class DatabaseService {
     if (oldVersion < 5) {
       await db.execute(createAdFreeEntitlementTableSql);
     }
+    if (oldVersion < 6) {
+      await db.execute(createAppUsageTableSql);
+    }
   }
 
   Future<void> _migrateToVehicleIdSchema(Database db) async {
@@ -188,6 +192,35 @@ class DatabaseService {
     );
   }
 
+  /// The earliest-known moment this app was ever used, across every device
+  /// this account has synced from — see [createAppUsageTableSql]. Recorded
+  /// once, the first time this is ever called with no existing row (a
+  /// fresh install with nothing to merge down yet); reinstalling *after*
+  /// cloud sync was connected instead pulls the original value back down
+  /// via [mergeAppUsageSql] before this is next called, so the new-user ad
+  /// grace period can't be replayed by reinstalling.
+  Future<DateTime> getOrCreateFirstUsedAt() async {
+    final rows = await _db.query('app_usage', where: 'id = 1', limit: 1);
+    if (rows.isNotEmpty) {
+      return DateTime.fromMillisecondsSinceEpoch(rows.single['first_used_at'] as int, isUtc: true);
+    }
+    final now = DateTime.now().toUtc();
+    await _db.insert('app_usage', {'id': 1, 'first_used_at': now.millisecondsSinceEpoch});
+    return now;
+  }
+
+  /// True if any vehicle or fuel entry row has local changes not yet
+  /// pushed to the cloud (see the `dirty` column note on this class).
+  /// Exposed only as this one yes/no signal, never the raw flag — it
+  /// drives [AppState.hasUnsyncedChanges], which the "not backed up" icon
+  /// reads.
+  Future<bool> hasDirtyRows() async {
+    final vehicleRows = await _db.query('vehicles', where: 'dirty = 1', limit: 1);
+    if (vehicleRows.isNotEmpty) return true;
+    final entryRows = await _db.query('fuel_entries', where: 'dirty = 1', limit: 1);
+    return entryRows.isNotEmpty;
+  }
+
   /// True if an active (non-deleted) vehicle other than [excludeId] already
   /// has this VIN. VIN must stay unique even though it's editable, so
   /// callers adding a new vehicle (no [excludeId]) or changing an existing