fix(portals): reload Stalker categories only for a held destination

Review follow-ups (Greptile, Codex): resetCategories() reloaded the
category resource, and the route session calls it on a portal switch
before the destination is resolved and on teardown, so it asked the
portal being left, and a failed destination lookup could let that answer
repopulate the sidebar. resetCategories() now only clears; the session
calls the new reloadCategories() after installing the destination, and
only when a handoff had already put that playlist in the store (the
owner, and so the resource params, did not change).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture/stalker-portal.md

@@ -397,8 +397,12 @@ Category arrays belong to `categoryPlaylistKey`, not just the content type.
 Every category reader checks that owner; a portal switch clears all four
 section caches before loading the destination. Aborted or foreign-portal
 responses (including errors and radio fallbacks) cannot write into the active
-cache. Explicit category resets reload even when the playlist object remains
-unchanged. This contract applies to collection details as well as routed
+cache. `resetCategories()` only clears: the route session calls it on a
+portal switch before the destination is resolved and on teardown, where a
+request would go to the portal being left. When a handoff had already put
+the destination in the store, the owner does not change and the resource
+would not reload by itself, so the session calls `reloadCategories()` once
+it has installed that playlist. This contract applies to collection details as well as routed
 catalogs, because both use the root Stalker store.
 
 Failure-handling rule:

docs/architecture/stalker-store-api-baseline.md

@@ -93,6 +93,9 @@ During refactor:
 - `clearSelectedItem(): void`
 - `setCategories(type: 'vod' | 'series' | 'itv' | 'radio', categories: StalkerCategoryItem[]): void`
 - `resetCategories(): void`
+  Clears only; it starts no request (called on portal switches and route teardown).
+- `reloadCategories(): void`
+  Refetches the current portal's categories after a reset that keeps the owner.
 - `setItvChannels(channels: StalkerItvChannel[]): void`
 - `setRadioChannels(channels: StalkerItvChannel[]): void`
 - `setSearchPhrase(phrase: string): void`

libs/portal/stalker/data-access/src/lib/stalker.store.compat.spec.ts

@@ -139,6 +139,7 @@ describe('StalkerStore API compatibility smoke', () => {
             'clearSelectedItem',
             'setCategories',
             'resetCategories',
+            'reloadCategories',
             'setItvChannels',
             'setSearchPhrase',
             'fetchVodSeriesEpisodes',

libs/portal/stalker/data-access/src/lib/stores/features/with-stalker-category-ownership.spec.ts

@@ -97,7 +97,21 @@ describe('Stalker category ownership', () => {
         void store.isCategoryResourceLoading();
     });
 
-    it('reloads categories when the active portal cache is explicitly reset', async () => {
+    it('sends no request on a reset alone', async () => {
+        request.mockResolvedValueOnce({
+            js: [{ id: '1', title: 'Before reset' }],
+        });
+        store.selectPlaylist('a');
+        await settle();
+        request.mockClear();
+
+        store.resetCategories();
+        await settle();
+
+        expect(request).not.toHaveBeenCalled();
+    });
+
+    it('reloads categories when the active portal cache is explicitly reloaded after a reset', async () => {
         request.mockResolvedValueOnce({
             js: [{ id: '1', title: 'Before reset' }],
         });
@@ -107,6 +121,7 @@ describe('Stalker category ownership', () => {
             js: [{ id: '1', title: 'After reset' }],
         });
         store.resetCategories();
+        store.reloadCategories();
         await settle();
         expect(
             store.getCategoryResource().map((c) => c.category_name)

libs/portal/stalker/data-access/src/lib/stores/features/with-stalker-content.feature.ts

@@ -1214,6 +1214,8 @@ export function withStalkerContent() {
                         ...buildCategoryPatch(type, categories),
                     });
                 },
+                // Clears only: called on portal switches and route teardown,
+                // where a reload would ask the portal being left.
                 resetCategories() {
                     patchState(store, {
                         vodCategories: [],
@@ -1222,6 +1224,13 @@ export function withStalkerContent() {
                         radioCategories: [],
                         categoryError: null,
                     });
+                },
+                /**
+                 * Refetches the current portal's categories. For a reset that
+                 * keeps the owner: the resource's params do not change then,
+                 * so it would not load on its own.
+                 */
+                reloadCategories() {
                     storeContext.categoryResource.reload();
                 },
                 setItvChannels(channels: StalkerItvChannel[]) {

libs/portal/stalker/feature/src/lib/stalker-workspace-route-session.service.spec.ts

@@ -71,6 +71,7 @@ describe('StalkerWorkspaceRouteSession', () => {
     const stalkerStore = {
         currentPlaylist,
         resetCategories: jest.fn(),
+        reloadCategories: jest.fn(),
         setSelectedCategory: jest.fn(),
         clearSelectedItem: jest.fn(),
         setCurrentPlaylist: jest.fn(
@@ -117,6 +118,7 @@ describe('StalkerWorkspaceRouteSession', () => {
         }));
 
         stalkerStore.resetCategories.mockClear();
+        stalkerStore.reloadCategories.mockClear();
         stalkerStore.setSelectedCategory.mockClear();
         stalkerStore.clearSelectedItem.mockClear();
         stalkerStore.setCurrentPlaylist.mockClear();
@@ -169,6 +171,46 @@ describe('StalkerWorkspaceRouteSession', () => {
         );
     });
 
+    // A switch must not ask the portal being left for categories: the new
+    // owner's params make the resource load on their own.
+    it('does not reload categories when the store switches portals', async () => {
+        currentPlaylist.set(OTHER_PLAYLIST);
+
+        TestBed.inject(StalkerWorkspaceRouteSession);
+        await flushEffects();
+
+        expect(stalkerStore.resetCategories).toHaveBeenCalled();
+        expect(currentPlaylist()?._id).toBe(PLAYLIST_ID);
+        expect(stalkerStore.reloadCategories).not.toHaveBeenCalled();
+    });
+
+    // A handoff installed the destination in the store first: the reset
+    // keeps the owner, so only an explicit reload brings the categories back.
+    it('reloads the cleared categories once a held destination is installed', async () => {
+        currentPlaylist.set(ACTIVE_PLAYLIST);
+
+        TestBed.inject(StalkerWorkspaceRouteSession);
+        await flushEffects();
+
+        expect(stalkerStore.reloadCategories).toHaveBeenCalledTimes(1);
+        expect(
+            stalkerStore.reloadCategories.mock.invocationCallOrder[0]
+        ).toBeGreaterThan(
+            stalkerStore.setCurrentPlaylist.mock.invocationCallOrder[0]
+        );
+    });
+
+    it('does not reload categories when the route is torn down', async () => {
+        TestBed.inject(StalkerWorkspaceRouteSession);
+        await flushEffects();
+        stalkerStore.reloadCategories.mockClear();
+
+        TestBed.resetTestingModule();
+
+        expect(stalkerStore.resetCategories).toHaveBeenCalled();
+        expect(stalkerStore.reloadCategories).not.toHaveBeenCalled();
+    });
+
     it('reconciles a revisited route when collection detail changed the shared store', async () => {
         const session = TestBed.inject(StalkerWorkspaceRouteSession);
         await flushEffects();

libs/portal/stalker/feature/src/lib/stalker-workspace-route-session.service.ts

@@ -140,6 +140,10 @@ export class StalkerWorkspaceRouteSession {
             this.currentPlaylistId !== playlistId ||
             this.stalkerStore.currentPlaylist()?._id !== playlistId
         ) {
+            // A handoff can install the destination in the store before this
+            // session does; the categories it held are cleared all the same.
+            const storeHeldDestination =
+                this.stalkerStore.currentPlaylist()?._id === playlistId;
             this.stalkerStore.resetCategories();
             this.stalkerStore.setSelectedCategory(null);
             this.stalkerStore.clearSelectedItem();
@@ -154,6 +158,9 @@ export class StalkerWorkspaceRouteSession {
             }
             await this.stalkerStore.setCurrentPlaylist(playlist);
             this.currentPlaylistId = playlistId;
+            // The owner did not change, so the category resource keeps its
+            // params and would not reload the cleared categories by itself.
+            if (storeHeldDestination) this.stalkerStore.reloadCategories();
         }
 
         if (generation !== this.syncGeneration || this.destroyRef.destroyed) {