fix(knowledge): hold stale items during refresh to eliminate flicker

lib/providers/knowledge_provider.dart

@@ -115,12 +115,43 @@ class KnowledgeNotifier extends Notifier<KnowledgeState> {
   }
 
   Future<void> refresh() async {
-    state = KnowledgeState(
-      noteType: state.noteType,
-      activeTags: state.activeTags,
-      searchQuery: state.searchQuery,
-    );
-    await _fetchFromScratch();
+    // Keep current items visible during re-fetch (no flicker).
+    try {
+      if (state.noteType == 'task') {
+        final tasks = await ref.read(tasksApiProvider).getAll();
+        final items = {
+          for (final t in tasks) t.id: KnowledgeItem.fromTask(t),
+        };
+        state = state.copyWith(
+          ids: tasks.map((t) => t.id).toList(),
+          items: items,
+          totalIds: tasks.length,
+          hasMore: false,
+        );
+        await _loadCounts();
+        return;
+      }
+
+      final (ids, total) = await _repo.fetchIds(
+        noteType: state.noteType,
+        tags: state.activeTags,
+        q: state.searchQuery,
+        limit: 50,
+        offset: 0,
+      );
+      // Hydrate the new IDs
+      final batch = await _repo.fetchBatch(ids);
+      final freshItems = {for (final item in batch) item.id: item};
+      state = state.copyWith(
+        ids: ids,
+        items: freshItems,
+        totalIds: total,
+        hasMore: ids.length < total,
+      );
+      await Future.wait([_loadCounts(), _loadTags()]);
+    } catch (_) {
+      // Silent — stale data is better than an error on refresh
+    }
   }
 
   // ── Scroll-triggered loaders ─────────────────────────────────────────────