fix(inbox): redirect to issue page when notification not in inbox

Shared inbox links (?issue=<id>) pointed to notifications that may no
longer exist in the current user's inbox (archived, or received by
someone else). The detail pane would fall back to an empty state and
leave the user stuck.

After inbox loads, if the selected key has no matching item, replace
the URL with /issues/<id> so the link still resolves to something
meaningful.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/views/inbox/components/inbox-page.tsx

@@ -61,6 +61,22 @@ export function InboxPage() {
     setSelectedKeyState(urlIssue);
   }, [urlIssue]);
 
+  const wsId = useWorkspaceId();
+  const { data: rawItems = [], isLoading: loading } = useQuery(inboxListOptions(wsId));
+  const items = useMemo(() => deduplicateInboxItems(rawItems), [rawItems]);
+
+  const selected = items.find((i) => (i.issue_id ?? i.id) === selectedKey) ?? null;
+
+  // Shared inbox links (?issue=<id>) may point to notifications not in this
+  // user's inbox (archived, or never received). Fall back to the issue page
+  // so the URL still resolves to something meaningful.
+  useEffect(() => {
+    if (loading) return;
+    if (!selectedKey) return;
+    if (selected) return;
+    replace(wsPaths.issueDetail(selectedKey));
+  }, [loading, selectedKey, selected, replace, wsPaths]);
+
   const setSelectedKey = useCallback((key: string) => {
     setSelectedKeyState(key);
     const inboxPath = wsPaths.inbox();
@@ -68,16 +84,11 @@ export function InboxPage() {
     replace(url);
   }, [replace, wsPaths]);
 
-  const wsId = useWorkspaceId();
-  const { data: rawItems = [], isLoading: loading } = useQuery(inboxListOptions(wsId));
-  const items = useMemo(() => deduplicateInboxItems(rawItems), [rawItems]);
-
   const { defaultLayout, onLayoutChanged } = useDefaultLayout({
     id: "multica_inbox_layout",
   });
 
   const isMobile = useIsMobile();
-  const selected = items.find((i) => (i.issue_id ?? i.id) === selectedKey) ?? null;
   const unreadCount = items.filter((i) => !i.read).length;
 
   const markReadMutation = useMarkInboxRead();