fix: clients sync to server terminals instead of creating new ones

- Remove auto-creation of terminal sessions from init/selectSession/switchAgent
- Clients only connect to existing alive terminals from server registry
- Remove localStorage persistence (agent/sessionId) — state derived from server
- Refine session-state types: new AgentStatus values, LastError interface
- UI improvements: AgentBadge, ChatContainer, UserInput, BashCard updates
- Simplify claude-hook routes, update session-state service

frontend/src/stores/session-state.ts

@@ -5,14 +5,15 @@ import { ref, computed } from 'vue'
 
 export type AgentStatus =
   | 'idle'
-  | 'processing'
+  | 'thinking'
   | 'reading'
   | 'writing'
   | 'toolUse'
-  | 'toolDone'
   | 'permissionRequest'
-  | 'notification'
+  | 'interrupted'
+  | 'error'
   | 'sessionStart'
+  | 'sessionEnd'
 
 export interface ActiveTool {
   name: string
@@ -48,6 +49,13 @@ export interface AgentTerminalInfo {
   connectedClients: number
 }
 
+export interface LastError {
+  tool: string
+  message: string
+  interrupted: boolean
+  timestamp: number
+}
+
 export interface AgentSessionState {
   agent: string
   sessionId: string | null
@@ -59,6 +67,7 @@ export interface AgentSessionState {
   currentTool: ActiveTool | null
   lastActivity: number
   lastStopResponse: string | null
+  lastError: LastError | null
   pendingApprovals: PendingApproval[]
   terminal: AgentTerminalInfo
   notifications: SessionNotification[]
@@ -130,6 +139,14 @@ export const useSessionState = defineStore('session-state', () => {
     )
   )
 
+  const isProcessing = computed(() =>
+    agentList.value.some(a => !['idle', 'sessionStart', 'sessionEnd'].includes(a.status))
+  )
+
+  const hasErrors = computed(() =>
+    agentList.value.some(a => a.status === 'error' || a.status === 'interrupted')
+  )
+
   const visibleNotifications = computed(() => {
     const now = Date.now()
     return agentList.value
@@ -199,6 +216,8 @@ export const useSessionState = defineStore('session-state', () => {
     anyPendingApprovals,
     totalPendingApprovals,
     allPendingApprovals,
+    isProcessing,
+    hasErrors,
     visibleNotifications,
     handleMessage,
     respondApproval,