feat: 接入 weixin 服务层与命令入口

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/services/weixin/permissions.ts

@@ -0,0 +1,73 @@
+import type { ChannelPermissionRequestParams } from '../mcp/channelNotification.js'
+
+export type PendingPermissionRequest = ChannelPermissionRequestParams & {
+  chatId: string
+  contextToken?: string
+  createdAt: number
+  expiresAt: number
+}
+
+export type ActivePermissionChat = {
+  chatId: string
+  contextToken?: string
+  updatedAt: number
+}
+
+const PENDING_PERMISSION_TTL_MS = 15 * 60 * 1000
+
+const pendingPermissions = new Map<string, PendingPermissionRequest>()
+let activePermissionChat: ActivePermissionChat | null = null
+
+function pruneExpiredPendingPermissions(now = Date.now()): void {
+  for (const [requestId, entry] of pendingPermissions.entries()) {
+    if (entry.expiresAt <= now) {
+      pendingPermissions.delete(requestId)
+    }
+  }
+}
+
+export function setActivePermissionChat(
+  chatId: string,
+  contextToken?: string,
+): void {
+  activePermissionChat = { chatId, contextToken, updatedAt: Date.now() }
+}
+
+export function getActivePermissionChat(): ActivePermissionChat | null {
+  return activePermissionChat
+}
+
+export function savePendingPermission(
+  request: ChannelPermissionRequestParams,
+  chatId: string,
+  contextToken?: string,
+): PendingPermissionRequest {
+  pruneExpiredPendingPermissions()
+  const entry: PendingPermissionRequest = {
+    ...request,
+    chatId,
+    contextToken,
+    createdAt: Date.now(),
+    expiresAt: Date.now() + PENDING_PERMISSION_TTL_MS,
+  }
+  pendingPermissions.set(request.request_id.toLowerCase(), entry)
+  return entry
+}
+
+export function consumePendingPermission(
+  requestId: string,
+  fromUserId: string,
+): PendingPermissionRequest | null {
+  pruneExpiredPendingPermissions()
+  const key = requestId.toLowerCase()
+  const entry = pendingPermissions.get(key)
+  if (!entry) return null
+  if (entry.chatId !== fromUserId) return null
+  pendingPermissions.delete(key)
+  return entry
+}
+
+export function clearPermissionStateForTests(): void {
+  pendingPermissions.clear()
+  activePermissionChat = null
+}