Update Pi packages to 0.79.9 and align pi-ask with current TUI/RPC behavior.
- guard custom ask/settings flows to TUI mode with a clear non-TUI fallback
- reset config cache on extension reload so edited settings are picked up
- clean up remote ask flow listeners on session shutdown
- forward editor focus/invalidation and keep @ file autocomplete explicit
- document the non-TUI contract and cover the compatibility fixes with tests
