Implement basic settings

lib/db.dart

@@ -28,6 +28,11 @@ CREATE TABLE IF NOT EXISTS scratches (
 );
 CREATE INDEX IF NOT EXISTS idx_scratches_date ON scratches (date);
 CREATE UNIQUE INDEX IF NOT EXISTS idx_scratches_date_unique ON scratches (date);
+
+CREATE TABLE IF NOT EXISTS settings (
+  key TEXT PRIMARY KEY NOT NULL,
+  value TEXT NOT NULL
+);
 ''';
 
   static Future<String> _getDatabasePath() async {
@@ -83,4 +88,27 @@ CREATE UNIQUE INDEX IF NOT EXISTS idx_scratches_date_unique ON scratches (date);
       rethrow;
     }
   }
+
+  // Settings Management
+  static Future<String?> getSetting(String key) async {
+    final List<Map<String, dynamic>> maps = await db.query(
+      'settings',
+      columns: ['value'],
+      where: 'key = ?',
+      whereArgs: [key],
+    );
+    if (maps.isNotEmpty) {
+      return maps.first['value'] as String?;
+    }
+    return null;
+  }
+
+  static Future<void> setSetting(String key, String value) async {
+    await db.insert(
+      'settings',
+      {'key': key, 'value': value},
+      conflictAlgorithm: ConflictAlgorithm.replace,
+    );
+    debugPrint("Setting updated: $key = $value");
+  }
 }