test: cover grid filter OR/AND (extract pure fn + unit + real e2e)

The two filter-search cases were test.fixme placeholders (expect(true).toBe(true)),
so the OR/AND chip rules were untested.

- Extract the grid-filter predicate from feed/+page.svelte into a pure
  filterUploads(uploads, filters) in $lib/feed-filter (behavior-preserving) and
  unit-test it (9 cases): tag OR, user OR, tag+user AND, AND-excludes-partial,
  case-insensitive caption match, null caption.
- Replace the e2e fixmes with real tests that seed known captions/uploaders, switch
  to grid view, activate chips via the search suggestions, and count grid tiles:
  OR widens 1→2, AND narrows 2→1.

Frontend unit: 27 passing. filter-search e2e: 3 passing.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

e2e/specs/03-feed/filter-search.spec.ts

@@ -1,29 +1,68 @@
 /**
- * USER_JOURNEYS.md §8 — search and filter chips. Asserts the OR / AND
- * combination rules described in the journey.
+ * USER_JOURNEYS.md §8 — grid-view search & filter chips. Verifies the OR / AND
+ * combination rules end-to-end by seeding uploads with known captions/uploaders,
+ * activating chips, and counting the resulting grid tiles.
  *
- * Most of this test currently drives the UI; the data-seeding happens
- * via API once a Node-side upload helper lands. For now we ship the
- * structure and the UI assertions, marked with `test.fixme` where they
- * depend on seeded data we can't yet create.
+ * (The pure combination logic is also unit-tested in
+ * frontend/src/lib/feed-filter.test.ts.)
  */
 import { test, expect } from '../../fixtures/test';
+import { seedUpload } from '../../helpers/seed';
+import type { Page } from '@playwright/test';
+
+/** Grid tiles render as buttons labelled "Upload anzeigen". */
+const tiles = (page: Page) => page.getByRole('button', { name: 'Upload anzeigen' });
+
+async function switchToGrid(page: Page) {
+  await page.getByRole('button', { name: 'Rasteransicht' }).click();
+}
+
+/** Type a query into the grid search box and click the matching suggestion. */
+async function addFilter(page: Page, query: string, suggestionName: string | RegExp) {
+  const search = page.getByPlaceholder('Nutzer oder #Tag suchen…');
+  await search.click();
+  await search.fill(query);
+  await page.getByRole('button', { name: suggestionName }).click();
+}
 
 test.describe('Feed — filter & search', () => {
-  test.fixme('two hashtag chips combine with OR', async ({ page, guest, signIn }) => {
-    const h = await guest('Searcher');
-    await signIn(page, h);
-    // TODO: seed 2 uploads with different hashtags, then activate two chips
-    // and assert both cards remain visible.
-    await page.goto('/feed');
-    expect(true).toBe(true);
+  test('two hashtag chips combine with OR', async ({ page, guest, signIn }) => {
+    const a = await guest('OrUser');
+    await seedUpload(a.jwt, { caption: 'pic #wedding' });
+    await seedUpload(a.jwt, { caption: 'pic #party' });
+    await seedUpload(a.jwt, { caption: 'pic #other' });
+
+    await signIn(page, a); // lands on /feed
+    await switchToGrid(page);
+    await expect(tiles(page)).toHaveCount(3);
+
+    // One tag → only its card.
+    await addFilter(page, '#wedding', /wedding/i);
+    await expect(tiles(page)).toHaveCount(1);
+
+    // Adding a second tag widens the result (OR), not narrows it.
+    await addFilter(page, '#party', /party/i);
+    await expect(tiles(page)).toHaveCount(2);
   });
 
-  test.fixme('uploader chip + hashtag chip combines with AND', async ({ page, guest, signIn }) => {
-    const h = await guest('Searcher2');
-    await signIn(page, h);
-    await page.goto('/feed');
-    expect(true).toBe(true);
+  test('uploader chip + hashtag chip combines with AND', async ({ page, guest, signIn }) => {
+    const alice = await guest('AndAlice');
+    const bob = await guest('AndBob');
+    await seedUpload(alice.jwt, { caption: 'pic #wedding' }); // Alice + wedding
+    await seedUpload(bob.jwt, { caption: 'pic #wedding' }); //   Bob   + wedding
+    await seedUpload(alice.jwt, { caption: 'pic #party' }); //   Alice + party
+
+    await signIn(page, alice); // feed is event-wide → sees all three
+    await switchToGrid(page);
+    await expect(tiles(page)).toHaveCount(3);
+
+    // Filter by uploader → Alice's two uploads.
+    await addFilter(page, 'AndAlice', 'AndAlice');
+    await expect(tiles(page)).toHaveCount(2);
+
+    // Add a tag → must satisfy BOTH (Alice AND #wedding) → just the one.
+    await addFilter(page, '#wedding', /wedding/i);
+    await expect(tiles(page)).toHaveCount(1);
   });
 
   test('feed page renders without crashing for an authed user', async ({ page, guest, signIn }) => {