fix(xtream): offer the learned panel clock to storage on every check

Review follow-up (Codex): a transient storage failure left the clock in the
store but not on the row, and the next check compared the answer with the
in-memory value and never retried. The resolved timezone is now always
handed to `transformPlaylistMeta`, whose row-level equality check keeps the
common case a read without a write; a failed write is retried by the next
account-info check.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

libs/portal/xtream/data-access/src/lib/stores/features/with-portal.feature.spec.ts

@@ -174,14 +174,36 @@ describe('withPortal', () => {
             expect(storedPlaylist.serverTimezone).toBe('UTC+03:00');
         });
 
-        it('does not rewrite the row when it already carries the value', async () => {
+        it('offers the value to storage every time but writes nothing when the row already carries it', async () => {
             storedPlaylist = { ...storedPlaylist, serverTimezone: 'UTC' };
             store.setCurrentPlaylist({ ...PLAYLIST, serverTimezone: 'UTC' });
             respondWith({ timezone: 'UTC' });
 
             await store.checkPortalStatus();
 
-            expect(transformPlaylistMeta).not.toHaveBeenCalled();
+            expect(transformPlaylistMeta).toHaveBeenCalledTimes(1);
+            const [, transform] = transformPlaylistMeta.mock.calls[0];
+            expect(transform(storedPlaylist)).toBeNull();
+        });
+
+        it('retries the write on the next check after a transient storage failure', async () => {
+            transformPlaylistMeta.mockImplementationOnce(() => {
+                throw new Error('storage unavailable');
+            });
+            respondWith({ timezone: 'Europe/London' });
+
+            await store.checkPortalStatus();
+            expect(store.currentPlaylist()?.serverTimezone).toBe(
+                'Europe/London'
+            );
+            expect(storedPlaylist.serverTimezone).toBeUndefined();
+
+            // The store already carries the clock, so only the row-level
+            // check may decide that the row still lacks it.
+            await store.checkPortalStatus();
+
+            expect(transformPlaylistMeta).toHaveBeenCalledTimes(2);
+            expect(storedPlaylist.serverTimezone).toBe('Europe/London');
         });
 
         it('keeps the previously known timezone when the response carries no usable clock', async () => {

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

@@ -193,10 +193,12 @@ export function withPortal() {
                                 },
                             });
                         }
-                        if (
-                            serverTimezone &&
-                            serverTimezone !== playlist.serverTimezone
-                        ) {
+                        // Always offered to storage, never gated on the
+                        // in-memory value: after a transient write failure
+                        // the store already carries the clock, and only the
+                        // row-level check inside the transform knows whether
+                        // the row does too.
+                        if (serverTimezone) {
                             await rememberServerTimezone(
                                 playlist.id,
                                 credentials,