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/server/src/types/ws-frames.ts

@@ -39,6 +39,12 @@ const ChatStatusValue = z.enum([
   'error',
 ]);
 
+// agent-status-normalize (#10): normalized per-(chat,agent) lifecycle status for
+// external coding agents (warm-acp / opencode / claude-sdk / pty). Distinct from
+// ChatStatusValue (native-inference chat lifecycle) — published by BooCoder's
+// dispatcher + permission flow on the per-session channel.
+const AgentStatusValue = z.enum(['working', 'blocked', 'idle', 'error']);
+
 const ErrorReasonValue = z.enum([
   'llm_provider_error',
   'doom_loop',
@@ -301,6 +307,21 @@ export const AgentCommandsFrame = z.object({
   commands: z.array(AgentCommandShape),
 });
 
+// agent-status-normalize (#10): published by BooCoder on the per-session channel
+// when an external agent's normalized status changes (turn start/end, permission
+// block/unblock). Keyed per (chat_id, agent); the frontend tracks the latest per
+// pair and resets on chat switch. `reason` is a free-form discriminator
+// (turn_start / turn_complete / failed / crashed / permission_request /
+// permission_resolved).
+export const AgentStatusUpdatedFrame = z.object({
+  type: z.literal('agent_status_updated'),
+  chat_id: Uuid,
+  agent: z.string().min(1),
+  status: AgentStatusValue,
+  reason: z.string().optional(),
+  at: IsoTimestamp,
+});
+
 // ---- discriminated union ---------------------------------------------------
 
 export const WsFrameSchema = z.discriminatedUnion('type', [
@@ -320,6 +341,7 @@ export const WsFrameSchema = z.discriminatedUnion('type', [
   PermissionRequestedFrame,
   PermissionResolvedFrame,
   AgentCommandsFrame,
+  AgentStatusUpdatedFrame,
   // per-user
   ChatStatusFrame,
   SessionUpdatedFrame,
@@ -361,6 +383,7 @@ export const KNOWN_FRAME_TYPES: readonly WsFrame['type'][] = [
   'permission_requested',
   'permission_resolved',
   'agent_commands',
+  'agent_status_updated',
   'chat_status',
   'session_updated',
   'session_renamed',