claude refactorings, flutter best practices, platform dependent changes, general cleanup

lib/utils/debouncer.dart

@@ -0,0 +1,34 @@
+import 'dart:async';
+
+/// Static map-based debouncer/throttler. Replaces the `easy_debounce` package
+/// with a minimal in-house implementation: each unique [tag] tracks its own
+/// pending Timer and gating flag.
+class Debouncer {
+  Debouncer._();
+
+  static final Map<String, Timer> _debounceTimers = {};
+  static final Map<String, Timer> _throttleTimers = {};
+
+  /// Coalesces calls under [tag]: the [action] runs once [delay] has elapsed
+  /// without further calls for the same tag.
+  static void debounce(String tag, Duration delay, void Function() action) {
+    _debounceTimers[tag]?.cancel();
+    _debounceTimers[tag] = Timer(delay, () {
+      _debounceTimers.remove(tag);
+      action();
+    });
+  }
+
+  /// Runs [action] immediately and ignores subsequent calls under the same
+  /// [tag] until [duration] has elapsed.
+  static void throttle(String tag, Duration duration, void Function() action) {
+    if (_throttleTimers.containsKey(tag)) return;
+    _throttleTimers[tag] = Timer(duration, () => _throttleTimers.remove(tag));
+    action();
+  }
+
+  static void cancel(String tag) {
+    _debounceTimers.remove(tag)?.cancel();
+    _throttleTimers.remove(tag)?.cancel();
+  }
+}