feat: normalized external-agent status (#10 scoped) (v2.7.6)

Scoped half of boocode_code_review_v2 §1 #10 — publish the agent status
BooCoder already observes (the config-injection notify-hook is the documented
follow-on, clean-room from superset ELv2).

- agent_status_updated WS frame (working|blocked|idle|error), server+web parity.
- Published from the dispatcher's turn boundaries (warm-acp/opencode/sdk/pty:
  working at start, idle/error at end) + the permission flow (blocked/working).
  Best-effort, never breaks a turn.
- Clean-room normalizeAgentEvent helper (superset's vendor-event -> Start/blocked
  /Stop collapse, event names as facts) + 25 tests — reused by the follow-on.
- AgentComposerBar status dot (distinct from the WS-liveness dot), tracked per
  (chat,agent) by a useAgentStatus map in CoderPane.

Built by 2 parallel agents vs a pinned frame contract. Server 545 + coder 294
tests passing (25 new); web tsc + builds clean; ws-frames parity green. Clears
the actionable review backlog (#1/#3/#4/#6-#12). Builds on v2.7.5.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/src/components/panes/CoderPane.tsx

@@ -18,6 +18,7 @@ import { mergeWireToolCall } from '@/lib/coder-tools';
 import { CoderMessageList, type CoderTimelineWire } from '@/components/panes/CoderMessageList';
 import { providerIcon, providerLabel } from '@/components/coder/providerIcons';
 import { refreshAgentSessions } from '@/hooks/useAgentSessions';
+import { useAgentStatus, type AgentStatus, type AgentStatusEntry } from '@/hooks/useAgentStatus';
 import { cn } from '@/lib/utils';
 
 // ---------------------------------------------------------------------------
@@ -80,6 +81,14 @@ interface WsHandlers {
   onAssistantComplete?: () => void;
   onAgentCommands?: (taskId: string, commands: AgentCommand[]) => void;
   onConnectedChange?: (connected: boolean) => void;
+  // #10: normalized external-agent status (working|blocked|idle|error) for the
+  // (chat,agent) carried on the frame. CoderPane records it in a live map and
+  // feeds the active agent's status to AgentComposerBar's status dot.
+  onAgentStatus?: (
+    chatId: string,
+    agent: string,
+    entry: AgentStatusEntry,
+  ) => void;
 }
 
 type RawCoderMessage = {
@@ -326,6 +335,19 @@ function useCoderMessages(sessionId: string, chatId: string | undefined, handler
               description: c.description,
             })),
           );
+        } else if (frame.type === 'agent_status_updated') {
+          // #10: { chat_id, agent, status, reason?, at }. The chat_id guard
+          // above already dropped cross-chat frames; record per (chat,agent).
+          const chatId = (frame.chat_id ?? scopedChatId) as string | undefined;
+          const agent = frame.agent as string | undefined;
+          const status = frame.status as AgentStatus | undefined;
+          if (chatId && agent && status) {
+            handlersRef.current.onAgentStatus?.(chatId, agent, {
+              status,
+              ...(frame.reason ? { reason: frame.reason as string } : {}),
+              at: (frame.at as string) ?? new Date().toISOString(),
+            });
+          }
         }
       } catch {
         // ignore unparseable frames
@@ -642,6 +664,8 @@ export function CoderPane({
     return groups;
   }, [agentCommands, skillItems, agentConfig.provider]);
 
+  // #10: live normalized status per (chat,agent), reset on chat switch below.
+  const agentStatus = useAgentStatus();
   const { messages, setMessages, connected, loadMessages } = useCoderMessages(sessionId, chatId, {
     onConnectedChange,
     onPermissionRequested: (prompt) => {
@@ -661,7 +685,21 @@ export function CoderPane({
     onAgentCommands: (_taskId, commands) => {
       setLiveTaskCommands(commands);
     },
+    onAgentStatus: agentStatus.record,
   });
+
+  // Clear any stale status for the previous chat when the pane switches chats so
+  // a lingering working/blocked dot never carries into the next conversation.
+  useEffect(() => {
+    return () => agentStatus.reset(chatId);
+  }, [chatId, agentStatus]);
+
+  // The active agent's normalized status for this chat. null for native boocode
+  // (no external status published) or before any frame arrives — gates the dot.
+  const currentAgentStatus: AgentStatusEntry | null =
+    agentConfig.provider && agentConfig.provider !== 'boocode'
+      ? agentStatus.get(chatId, agentConfig.provider)
+      : null;
   const { changes, loading, refresh, approve, reject } = usePendingChanges(sessionId);
   const { checkpointMessageIds, refreshCheckpoints } = useCheckpoints(sessionId, chatId);
   const [input, setInput] = useState('');
@@ -968,6 +1006,7 @@ export function CoderPane({
         connected={connected}
         sessionId={sessionId}
         hasPriorTurn={hasPriorTurn}
+        agentStatus={currentAgentStatus}
       />
       {/* Chat area — BooChat-style timeline (text + tool runs as siblings) */}
       <div className="flex-1 min-h-0 flex flex-col">