fix(tests): uuid-suffixed websocket collection self-deletes

TestWebSocketUserScopedBroadcast creates "Admin Collection <uuid8>" on
the shared admin — deliberately NOT named with "test" or every run
would 409 on UNIQUE(user_id, name) against stranded past-run rows
(the comment in the test says exactly that), but it never deleted its
row, so the same runs accrued ten "Admin Collection" forever-rows the
name sweep can never touch. cleanupCollectionByID gives tests an
owner-scoped RLS-bridge delete-at-backstory: same minimal contract as
cleanupDeviceByIdentifier, for rows whose name must stay unique across
runs. Deleted the ten standing rows (owner-scoped, exactly what the
cleanup path does).

What CANNOT be swept, audited safe: the dev admin's real hand-made
collections (Saga reading-orders, Podcast 2, Smart Collection (Books))
carry no sweepable names; devices rely on identifier/token prefixes
tests own exclusively; the rls-phone hand account persists because the
transient-user sweep matches only @tests.bookhoard.internal /
@example.com emails.

cmd/server/tests/test_helpers_test.go

@@ -111,6 +111,28 @@ func cleanupDeviceByIdentifier(t *testing.T, setup *TestServerSetup, identifier
 	})
 }
 
+// cleanupCollectionByID deletes one collections row at test end, scoped
+// through the RLS bridge to its owner — collections RLS (2026-10-31)
+// makes unscoped writes invisible (no-op). Use for a collection a test
+// attaches to the shared admin whose name CANNOT carry the "test"
+// marker the setup-time name sweep keys on (uuid-suffixed uniqueness
+// against stale UNIQUE(user_id, name) rows from past runs). Rows that
+// survive their test also get stranded forever — the 10 accumulated
+// "Admin Collection <uuid>" rows were exactly this.
+func cleanupCollectionByID(t *testing.T, setup *TestServerSetup, ownerID [16]byte, collectionID string) {
+	t.Cleanup(func() {
+		cid, err := uuid.Parse(collectionID)
+		if err != nil {
+			t.Logf("cleanupCollectionByID: unparsable id %q — %v", collectionID, err)
+			return
+		}
+		scope := rls.WithUser(context.Background(), pgtype.UUID{Bytes: ownerID, Valid: true})
+		if err := setup.DB.DeleteCollection(scope, pgtype.UUID{Bytes: cid, Valid: true}); err != nil {
+			t.Logf("cleanupCollectionByID: delete failed for %s — %v", collectionID, err)
+		}
+	})
+}
+
 // Close cleans up all resources in the correct order
 func (s *TestServerSetup) Close() error {
 	s.mu.Lock()

cmd/server/tests/websocket_test.go

@@ -241,6 +241,10 @@ func TestWebSocketUserScopedBroadcast(t *testing.T) {
 	err = json.NewDecoder(collectionResp.Body).Decode(&collectionResult)
 	require.NoError(t, err)
 	collectionID := collectionResult["id"].(string)
+	// The uuid suffix keeps the name off every run's UNIQUE(user_id,name),
+	// which also keeps it out of the name-based cleanup sweep — self-delete
+	// instead (owner-scoped, exactly who created it).
+	cleanupCollectionByID(t, setup, getTestUserID(t, setup.DB), collectionID)
 
 	// Create a test book via API
 	bookID := createTestMediaItemID(t, setup)