feat: add hook event history with badge counts in SessionLifecycleStatus

Server persists hookHistory[] per agent (cap 500, resets on SessionStart),
synced realtime via session-state-patch. Frontend computes event counts
by macro type and renders color-coded badges at the ribbon start.
Mock mode also accumulates badges during demo sequence.

server/services/session-state.ts

@@ -32,6 +32,12 @@ export interface PendingApproval {
   timestamp: number
 }
 
+export interface HookHistoryEntry {
+  event: string
+  timestamp: number
+  detail?: string
+}
+
 export interface SessionNotification {
   id: string
   event: string
@@ -72,6 +78,9 @@ export interface AgentSessionState {
   pendingApprovals: PendingApproval[]
   terminal: AgentTerminalInfo
   notifications: SessionNotification[]
+  hookHistory: HookHistoryEntry[]
+  lastHookEvent: string | null
+  lastHookDetail: string | null
 }
 
 export interface HookPayload {
@@ -114,6 +123,7 @@ export interface SessionStatePatch {
 // ── Notification builders ──
 
 const MAX_NOTIFICATIONS = 30
+const MAX_HOOK_HISTORY = 500
 const TTL_INFO = 3500
 const TTL_WARNING = 5000
 
@@ -219,6 +229,9 @@ function createDefaultState(agent: string): AgentSessionState {
       connectedClients: 0,
     },
     notifications: [],
+    hookHistory: [],
+    lastHookEvent: null,
+    lastHookDetail: null,
   }
 }
 
@@ -236,7 +249,7 @@ class SessionStateManager {
 
   /** Process a raw hook event and return the patch to broadcast */
   processHookEvent(payload: HookPayload): SessionStatePatch {
-    const agentName = payload.agent_name || 'main'
+    const agentName = payload.agent_name || 'claude'
     const state = this.getOrCreateAgent(agentName)
     const now = Date.now()
 
@@ -246,6 +259,8 @@ class SessionStateManager {
     // Build patch
     const patch: Partial<AgentSessionState> = {
       lastActivity: now,
+      lastHookEvent: payload.hook_event_name || null,
+      lastHookDetail: payload.tool_name || payload.message || null,
     }
 
     // Only update status/tool if deriveStatus returned a result
@@ -310,6 +325,20 @@ class SessionStateManager {
     const updatedNotifications = [...state.notifications, notification].slice(-MAX_NOTIFICATIONS)
     patch.notifications = updatedNotifications
 
+    // Build hook history entry
+    const historyEntry: HookHistoryEntry = {
+      event: payload.hook_event_name || 'unknown',
+      timestamp: now,
+    }
+    const historyDetail = payload.tool_name || payload.message
+    if (historyDetail) historyEntry.detail = historyDetail as string
+
+    if (payload.hook_event_name === 'SessionStart') {
+      patch.hookHistory = [historyEntry]
+    } else {
+      patch.hookHistory = [...state.hookHistory, historyEntry].slice(-MAX_HOOK_HISTORY)
+    }
+
     // Apply patch to state
     Object.assign(state, patch)
 
@@ -372,6 +401,23 @@ class SessionStateManager {
     return this.agents.get(agent) || null
   }
 
+  /** Find agent name by session_id */
+  findAgentBySessionId(sessionId: string): string | null {
+    for (const [name, state] of this.agents) {
+      if (state.sessionId === sessionId) return name
+    }
+    return null
+  }
+
+  /** Find all agents matching a transcript_path */
+  findAgentsByTranscript(transcriptPath: string): string[] {
+    const matches: string[] = []
+    for (const [name, state] of this.agents) {
+      if (state.transcriptPath === transcriptPath) matches.push(name)
+    }
+    return matches
+  }
+
   /** Clean up expired notifications (call periodically) */
   cleanExpiredNotifications(): void {
     const now = Date.now()