Add 'show ready' command to list available tasks

Let user see what tasks are available to work on.

Trigger

User sends: 'ready' or 'what can I work on' or 'show tasks'

Response

'Ready tasks: • t-229 [P2] Split Biz/PodcastItLater/Web.py • t-231 [P2] Split Biz/PodcastItLater/Core.py • t-257 [P2] Build web UI to inspect notes

Reply with a task ID to start work.'

Implementation

• Call task ready (via Omni.Task.Core or subprocess)
• Format as compact list
• Maybe add inline keyboard buttons for top 3