fix(chat): restore anchor + in-flight indicator + cold-start session restore

Three issues surfaced by review:

1. ContextAnchorButton always disabled on /:slug/chat — useRouteAnchorCandidate
   only matches issue/project/inbox pathnames, so moving chat to its own route
   dropped 'bring the page I was on into the conversation'. Track the last
   anchor-eligible location globally (new useAnchorTracker mounted in AppSidebar
   + lastAnchorLocation on useChatStore) and substitute it when on /chat.

2. No global 'Multica is working' cue after ChatFab deletion. Subscribe the
   sidebar Chat entry to pendingChatTasksOptions and swap the unread dot for a
   spinner while any chat task is in flight.

3. ChatPage restore effect latched didRestoreRef before the sessions query
   resolved, so cold-start direct nav to /chat landed on the empty state even
   when the server had an active session. Wait for isSuccess before locking
   the ref.

packages/core/chat/store.ts

@@ -78,12 +78,20 @@ export interface ChatState {
    * the preference survives workspace switches and reloads.
    */
   focusMode: boolean;
+  /**
+   * Last location where a context anchor could be derived (issue/project/inbox).
+   * Updated globally by useAnchorTracker; used as a fallback for the Chat page
+   * which is its own route and therefore has no anchor of its own.
+   * Not persisted — resets per session; focus mode itself persists.
+   */
+  lastAnchorLocation: { pathname: string; search: string } | null;
   setActiveSession: (id: string | null) => void;
   setSelectedAgentId: (id: string) => void;
   /** sessionId accepts a real session UUID or DRAFT_NEW_SESSION. */
   setInputDraft: (sessionId: string, draft: string) => void;
   clearInputDraft: (sessionId: string) => void;
   setFocusMode: (on: boolean) => void;
+  setLastAnchorLocation: (loc: { pathname: string; search: string } | null) => void;
 }
 
 export interface ChatStoreOptions {
@@ -103,6 +111,8 @@ export function createChatStore(options: ChatStoreOptions) {
     selectedAgentId: storage.getItem(wsKey(AGENT_STORAGE_KEY)),
     inputDrafts: readDrafts(storage, wsKey(DRAFTS_KEY)),
     focusMode: storage.getItem(FOCUS_MODE_KEY) === "true",
+    lastAnchorLocation: null,
+    setLastAnchorLocation: (loc) => set({ lastAnchorLocation: loc }),
     setActiveSession: (id) => {
       logger.info("setActiveSession", { from: get().activeSessionId, to: id });
       if (id) {

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

@@ -55,7 +55,9 @@ export function ChatPage() {
   const user = useAuthStore((s) => s.user);
   const { data: agents = [] } = useQuery(agentListOptions(wsId));
   const { data: members = [] } = useQuery(memberListOptions(wsId));
-  const { data: sessions = [] } = useQuery(chatSessionsOptions(wsId));
+  const { data: sessions = [], isSuccess: sessionsLoaded } = useQuery(
+    chatSessionsOptions(wsId),
+  );
   const { data: allSessions = [] } = useQuery(allChatSessionsOptions(wsId));
   const { data: rawMessages, isLoading: messagesLoading } = useQuery(
     chatMessagesOptions(activeSessionId ?? ""),
@@ -87,16 +89,20 @@ export function ChatPage() {
     availableAgents[0] ??
     null;
 
-  // Restore most recent active session once on mount.
+  // Restore most recent active session once the session query resolves.
+  // The ref is set only AFTER we've seen a successful query — setting it
+  // unconditionally on first render would lose the restore whenever the
+  // page mounts before the query returns (cold-start / direct navigate).
   const didRestoreRef = useRef(false);
   useEffect(() => {
     if (didRestoreRef.current) return;
+    if (!sessionsLoaded) return;
     didRestoreRef.current = true;
-    if (activeSessionId || sessions.length === 0) return;
+    if (activeSessionId) return;
     const latest = sessions.find((s) => s.status === "active");
     if (latest) setActiveSession(latest.id);
     // eslint-disable-next-line react-hooks/exhaustive-deps -- run once when sessions load
-  }, [sessions]);
+  }, [sessionsLoaded, sessions]);
 
   // Auto mark-as-read whenever the viewer is on a session with unread.
   const currentHasUnread =

packages/views/chat/components/context-anchor.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import { useEffect } from "react";
 import { useQuery } from "@tanstack/react-query";
 import { Focus } from "lucide-react";
 import type { ContextAnchor } from "@multica/core/chat";
@@ -33,11 +34,42 @@ export function buildAnchorMarkdown(anchor: ContextAnchor): string {
   return `Context: Project "${anchor.label}"`;
 }
 
+/**
+ * Returns true when the given pathname can resolve to an anchor candidate
+ * (issue detail, project detail, or inbox). Used by both the resolver and
+ * the tracker so they agree on which routes are anchor-eligible.
+ */
+function isAnchorEligiblePath(pathname: string): boolean {
+  if (/^\/[^/]+\/issues\/[^/]+$/.test(pathname)) return true;
+  if (/^\/[^/]+\/projects\/[^/]+$/.test(pathname)) return true;
+  if (/^\/[^/]+\/inbox$/.test(pathname)) return true;
+  return false;
+}
+
+/**
+ * Runs an effect that remembers the last anchor-eligible location the user
+ * visited. Mount this in a component that's present on every page (the app
+ * sidebar) so the chat page — which is its own route and therefore has no
+ * anchor of its own — can still know what the user was just looking at.
+ */
+export function useAnchorTracker(): void {
+  const { pathname, searchParams } = useNavigation();
+  const setLastAnchorLocation = useChatStore((s) => s.setLastAnchorLocation);
+  useEffect(() => {
+    if (!isAnchorEligiblePath(pathname)) return;
+    setLastAnchorLocation({ pathname, search: searchParams.toString() });
+  }, [pathname, searchParams, setLastAnchorLocation]);
+}
+
 /**
  * Resolve the current page into an anchorable candidate, or null if the user
  * is somewhere without a natural focus object. Subscribes via react-query so
  * the result updates the instant the relevant cache fills.
  *
+ * When the user is on the Chat route (no intrinsic anchor), falls back to
+ * the last anchor-eligible location remembered by `useAnchorTracker`, so
+ * "open Chat from an issue → focus mode still attaches that issue" works.
+ *
  * `wsId` is passed in (per CLAUDE.md convention) so this hook works outside
  * a WorkspaceIdProvider if ever reused elsewhere.
  */
@@ -46,10 +78,20 @@ export function useRouteAnchorCandidate(wsId: string): {
   isResolving: boolean;
 } {
   const { pathname, searchParams } = useNavigation();
+  const lastAnchorLocation = useChatStore((s) => s.lastAnchorLocation);
 
-  const issueMatch = pathname.match(/^\/[^/]+\/issues\/([^/]+)$/);
-  const projectMatch = pathname.match(/^\/[^/]+\/projects\/([^/]+)$/);
-  const isInbox = /^\/[^/]+\/inbox$/.test(pathname);
+  // On the Chat route there's no intrinsic anchor; substitute the last
+  // anchor-eligible location the user visited. Anywhere else, use the
+  // live route directly.
+  const useFallback = !isAnchorEligiblePath(pathname) && !!lastAnchorLocation;
+  const effectivePath = useFallback ? lastAnchorLocation!.pathname : pathname;
+  const effectiveSearch = useFallback
+    ? new URLSearchParams(lastAnchorLocation!.search)
+    : searchParams;
+
+  const issueMatch = effectivePath.match(/^\/[^/]+\/issues\/([^/]+)$/);
+  const projectMatch = effectivePath.match(/^\/[^/]+\/projects\/([^/]+)$/);
+  const isInbox = /^\/[^/]+\/inbox$/.test(effectivePath);
 
   const routeIssueId = issueMatch ? decodeURIComponent(issueMatch[1]!) : null;
   const routeProjectId = projectMatch
@@ -61,7 +103,7 @@ export function useRouteAnchorCandidate(wsId: string): {
     ...inboxListOptions(wsId),
     enabled: isInbox,
   });
-  const inboxKey = isInbox ? searchParams.get("issue") : null;
+  const inboxKey = isInbox ? effectiveSearch.get("issue") : null;
   const inboxSelectedIssueId =
     isInbox && inboxKey
       ? inboxItems.find((i) => (i.issue_id ?? i.id) === inboxKey)?.issue_id ??

packages/views/layout/app-sidebar.tsx

@@ -30,6 +30,7 @@ import {
   CircleUser,
   FolderKanban,
   MessageSquare,
+  Loader2,
   X,
   Zap,
 } from "lucide-react";
@@ -66,7 +67,8 @@ import { useCurrentWorkspace, useWorkspacePaths, paths } from "@multica/core/pat
 import { workspaceListOptions, myInvitationListOptions, workspaceKeys } from "@multica/core/workspace/queries";
 import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
 import { inboxKeys, deduplicateInboxItems } from "@multica/core/inbox/queries";
-import { chatSessionsOptions } from "@multica/core/chat/queries";
+import { chatSessionsOptions, pendingChatTasksOptions } from "@multica/core/chat/queries";
+import { useAnchorTracker } from "../chat/components/context-anchor";
 import { api } from "@multica/core/api";
 import { useModalStore } from "@multica/core/modals";
 import { useMyRuntimesNeedUpdate } from "@multica/core/runtimes/hooks";
@@ -334,6 +336,14 @@ export function AppSidebar({ topSlot, searchSlot, headerClassName, headerStyle }
     () => chatSessions.some((s) => s.has_unread),
     [chatSessions],
   );
+  const { data: pendingChatTasks } = useQuery({
+    ...pendingChatTasksOptions(wsId ?? ""),
+    enabled: !!wsId,
+  });
+  const hasChatRunning = (pendingChatTasks?.tasks.length ?? 0) > 0;
+  // Track last anchor-eligible route so the Chat page (which is its own route)
+  // can still resolve focus-mode context from the page the user was just on.
+  useAnchorTracker();
   const hasRuntimeUpdates = useMyRuntimesNeedUpdate(wsId);
   const { data: pinnedItems = EMPTY_PINS } = useQuery({
     ...pinListOptions(wsId ?? "", userId ?? ""),
@@ -588,7 +598,10 @@ export function AppSidebar({ topSlot, searchSlot, headerClassName, headerStyle }
                             {unreadCount > 99 ? "99+" : unreadCount}
                           </span>
                         )}
-                        {item.label === "Chat" && hasChatUnread && (
+                        {item.label === "Chat" && hasChatRunning && (
+                          <Loader2 className="ml-auto !size-3 animate-spin text-muted-foreground" />
+                        )}
+                        {item.label === "Chat" && !hasChatRunning && hasChatUnread && (
                           <span className="ml-auto size-1.5 rounded-full bg-brand" />
                         )}
                       </SidebarMenuButton>