[mob][photos] SemanticSearchService minor changes

mobile/lib/services/machine_learning/semantic_search/semantic_search_service.dart

@@ -61,6 +61,7 @@ class SemanticSearchService {
     await EmbeddingsDB.instance.init();
     await _loadImageEmbeddings();
     Bus.instance.on<EmbeddingUpdatedEvent>().listen((event) {
+      if (!_hasInitialized) return;
       _embeddingLoaderDebouncer.run(() async {
         await _loadImageEmbeddings();
       });
@@ -74,6 +75,13 @@ class SemanticSearchService {
     });
   }
 
+  Future<void> dispose() async {
+    if (!_hasInitialized) return;
+    _hasInitialized = false;
+    await ClipTextEncoder.instance.release();
+    _cachedImageEmbeddings.clear();
+  }
+
   Future<void> sync() async {
     if (_isSyncing) {
       return;
@@ -90,6 +98,11 @@ class SemanticSearchService {
         _cachedImageEmbeddings.isNotEmpty;
   }
 
+  bool bothClipModelsLoaded() {
+    return ClipImageEncoder.instance.isInitialized &&
+        ClipTextEncoder.instance.isInitialized;
+  }
+
   // searchScreenQuery should only be used for the user initiate query on the search screen.
   // If there are multiple call tho this method, then for all the calls, the result will be the same as the last query.
   Future<(String, List<EnteFile>)> searchScreenQuery(String query) async {