D3-12 Session Resilience Design

Objective

Design the backend lifecycle rules that let long-running tasks survive frontend disconnects while stale sessions and runaway processes are cleaned up.

Inputs

• docs/BACKEND_MEMBRANE_PROBE_REPORT.md
• docs/LIVE_BRIDGE_VALIDATION_REPORT.md if available
• Pi Linux capabilities

Scope

• Choose async dispatch method: detached process, systemd user transient unit, queue, or equivalent.
• Design mailbox/pending message persistence.
• Design session timeout rules.
• Design rogue process TTL and memory ceilings.
• Keep moving parts minimal.