Low-Context Execution Packet

Use branch stage/d3-12-session-resilience-design.

Design only. Do not implement the reaper or mailbox in this stage.

docs/SESSION_RESILIENCE_MANIFEST.md must include:

1. Async dispatch choice
2. Mailbox storage choice
3. SQLite schema or flat-file format
4. Session state machine
5. Reconnect handshake
6. Duplicate-prevention rules
7. Interactive prompt timeout
8. Sub-agent TTL
9. Memory/process limits
10. Reaper audit interval
11. D3-13 implementation checklist

Default values unless data argues otherwise:

interactive_prompt_timeout_seconds=300
background_task_default_ttl_seconds=1800
background_task_hard_ttl_seconds=3600
reaper_interval_seconds=60
mailbox_flush_batch_size=50

Preferred persistence:

• SQLite if D3-10 already uses Python and needs atomic ack/delete
• append-only JSONL only if SQLite is unavailable or overkill
• avoid Redis/RabbitMQ unless D3-10 already introduced it and measured acceptable overhead

Mailbox schema must include:

id,session_id,message_id,sender,body,created_ms,delivered_ms,delivery_attempts

The design must explicitly state what happens when the RG powers off mid-command and when it reconnects later.