Add built-in scheduler with group-scoped tasks

- Custom nanoclaw MCP server with scheduling tools (schedule_task,
  list_tasks, get_task, update_task, pause/resume/cancel_task, send_message)
- Tasks run as full agents in their group's context
- Support for cron, interval, and one-time schedules
- Task run logging with duration and results
- Main channel has Bash access for admin tasks (query DB, manage groups)
- Other groups restricted to file operations only
- Updated docs and requirements

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/types.ts

@@ -17,3 +17,26 @@ export interface NewMessage {
   content: string;
   timestamp: string;
 }
+
+export interface ScheduledTask {
+  id: string;
+  group_folder: string;
+  chat_jid: string;
+  prompt: string;
+  schedule_type: 'cron' | 'interval' | 'once';
+  schedule_value: string;
+  next_run: string | null;
+  last_run: string | null;
+  last_result: string | null;
+  status: 'active' | 'paused' | 'completed';
+  created_at: string;
+}
+
+export interface TaskRunLog {
+  task_id: string;
+  run_at: string;
+  duration_ms: number;
+  status: 'success' | 'error';
+  result: string | null;
+  error: string | null;
+}