Fix scheduled tasks and improve task scheduling UX

- Fix Apple Container mount issue: move groups/CLAUDE.md to groups/global/
  directory (Apple Container only supports directory mounts, not file mounts)
- Fix scheduled tasks for main group: properly detect isMain based on
  group_folder instead of always setting false
- Add isScheduledTask flag so agent knows when running as scheduled task
- Improve schedule_task tool description with clear format examples for
  cron, interval, and once schedule types
- Update global CLAUDE.md with instructions for scheduled tasks to use
  mcp__nanoclaw__send_message when needed

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

groups/global/CLAUDE.md

@@ -21,6 +21,15 @@ If a request requires significant work (research, multiple steps, file operation
 
 This keeps users informed instead of waiting in silence.
 
+## Scheduled Tasks
+
+When you run as a scheduled task (no direct user message), use `mcp__nanoclaw__send_message` if needed to communicate with the user. Your return value is only logged internally - it won't be sent to the user.
+
+Example: If your task is "Share the weather forecast", you should:
+1. Get the weather data
+2. Call `mcp__nanoclaw__send_message` with the formatted forecast
+3. Return a brief summary for the logs
+
 ## Your Workspace
 
 Files you create are saved in `/workspace/group/`. Use this for notes, research, or anything that should persist.

groups/main/CLAUDE.md

@@ -147,7 +147,7 @@ Read `/workspace/project/data/registered_groups.json` and format it nicely.
 
 ## Global Memory
 
-You can read and write to `/workspace/project/groups/CLAUDE.md` for facts that should apply to all groups. Only update global memory when explicitly asked to "remember this globally" or similar.
+You can read and write to `/workspace/project/groups/global/CLAUDE.md` for facts that should apply to all groups. Only update global memory when explicitly asked to "remember this globally" or similar.
 
 ---