feat: preserve scroll position during note list resets

- Added scroll position preservation when resetting note list (e.g. during searches)
- Implemented willReset signal in PaginationService to notify views before data resets
- Created preserveOnReset effect to capture scroll offset before list changes
- Added restoreAfterReset effect to restore scroll position after data reloads
- Updated loadInitial and invalidateCache methods to trigger willReset notifications

src/app/features/list/paginated-notes-list.component.ts

@@ -319,6 +319,7 @@ export class PaginatedNotesListComponent implements OnInit, OnDestroy {
   readonly contextMenu = inject(NoteContextMenuService);
   private editorState = inject(EditorStateService);
   private destroy$ = new Subject<void>();
+  private preservedOffset: number | null = null;
 
   @ViewChild(CdkVirtualScrollViewport) viewport?: CdkVirtualScrollViewport;
 
@@ -603,6 +604,38 @@ export class PaginatedNotesListComponent implements OnInit, OnDestroy {
   });
 
   // Effects
+  // Capture current scroll anchor BEFORE a data reset (e.g., new search), then restore it after reload
+  private preserveOnReset = effect(() => {
+    // react to reset notifications
+    const _tick = this.paginationService.onWillReset();
+    // when incremented, capture current rendered start index as anchor
+    const vp = this.viewport;
+    if (vp) {
+      try {
+        this.preservedOffset = Math.max(0, vp.measureScrollOffset());
+      } catch {
+        this.preservedOffset = 0;
+      }
+    } else {
+      this.preservedOffset = 0;
+    }
+  });
+
+  // After items recompute following a reset, scroll back to the preserved index once
+  private restoreAfterReset = effect(() => {
+    // Trigger on recompute
+    this.visibleNotes();
+    const offset = this.preservedOffset;
+    if (offset != null) {
+      // Defer to next microtask to ensure viewport has measured
+      queueMicrotask(() => {
+        const vp = this.viewport;
+        if (!vp) return;
+        try { vp.scrollToOffset(offset, 'auto'); } catch {}
+        this.preservedOffset = null;
+      });
+    }
+  });
   private syncQuery = effect(() => {
     this.q.set(this.query() || '');
     // If external query changes (e.g., URL/state), refresh pagination to match

src/app/services/pagination.service.ts

@@ -28,6 +28,8 @@ export class PaginationService {
   private isLoading = signal(false);
   private searchTerm = signal('');
   private totalItems = signal(0);
+  // Notifier fired BEFORE pages reset, so views can capture scroll anchors
+  private willReset = signal(0);
 
   // Computed properties
   readonly allItems = computed(() => {
@@ -43,10 +45,14 @@ export class PaginationService {
   readonly canLoadMore = computed(() => this.hasMorePages() && !this.isLoading());
   readonly isLoadingMore = this.isLoading;
   readonly hasMore = this.hasMorePages;
+  // Expose reset notifier so views can preserve scroll position across resets
+  readonly onWillReset = this.willReset;
 
   // Load initial page
   async loadInitial(search = ''): Promise<void> {
     this.searchTerm.set(search);
+    // Notify listeners that a reset is imminent
+    this.willReset.update(v => v + 1);
     this.pages.set(new Map());
     this.currentCursor.set(null);
     this.hasMorePages.set(true);
@@ -103,6 +109,8 @@ export class PaginationService {
 
   // Invalidate cache (after file changes)
   invalidateCache(): void {
+    // Notify listeners that a reset is imminent
+    this.willReset.update(v => v + 1);
     this.pages.set(new Map());
     this.currentCursor.set(null);
     this.hasMorePages.set(true);