Salvaged from PR #97815 by @itsflownium, slimmed to the schema-free core:
- TodoStore gains a monotonic in-memory revision; the todo tool result
returns it so clients can reject stale updates
- tui_gateway emits a dedicated todo.updated full-snapshot event that
bypasses optional tool-progress display settings
- session resume/activate responses attach the authoritative todo
snapshot; renderer restores it with revision arbitration
- desktop store tracks per-session revisions and rejects regressions
The session_todo_state DB table from the original PR is intentionally
dropped: canonical todo tool results already persist in conversation
history, so resume paths derive the snapshot from the stored transcript
instead of a parallel store.
393af4a310