v0.9.5: prompt-scoped file recovery (restore workspace from a prior prompt)

[Hmbown]

Goal

From a prior user prompt, restore the workspace files that turn wrote (session snapshots) — not only transcript scrollback. Confirm before destructive restore; cooperate with git (do not discard user commits).

Why

When an agent damages the tree, recovery today is mostly git archaeology or transcript nostalgia. Prompt-scoped file restore makes “undo that turn’s writes” a product feature.

Current state (codewhale)

• Session/history and checkpoint/artifact storage under ~/.codewhale/sessions/
• crates/tui/src/tui/history/, crates/state/
• Sandbox / execpolicy presentation paths (recovery must not fight safety docs)

Target

1. Extend existing checkpoint/session artifact storage so each user prompt can be associated with a file snapshot of writes from that turn (or a documented equivalent restore set).
2. Operator UI/command to pick a prior prompt and restore those files after confirmation.
3. Play with git: never silently discard user commits; prefer restore that is reviewable (diff/confirm).
4. Document lifetime, location, and opt-out/cleanup.

Acceptance criteria

• Restore files from a prompt-scoped checkpoint with an explicit confirm step
• Restored set matches what that turn wrote (or docs honestly bound what is covered)
• No silent discard of user commits
• Docs for location, lifetime, sharing/cleanup, opt-out
• Tests for missing checkpoint, partial snapshot, and confirm-cancel
• Suite green; just fmt clean

Non-goals

• Full VCS replacement or magit-style UI
• Rewinding chat-only without files (already have history)
• Sandbox policy redesign

Depends on

Optional in the craft set — can ship after turn honesty and mid-turn control. Benefits from clearer session metadata (#5262) but can use current session store.

Related

Drive-while-working craft set.

[Hmbown]

Part of the v0.9.5 drive-while-working craft set: #5267 (stop honesty) → #5268 (mid-turn) → #5269 (plan artifact) → #5270 (tasks) → #5271 (peek) → #5272 (file recovery).

[Hmbown]

Direction overlay (2026-08-07): the patch/diff core stays Rust (the security/perf 'teeth' of the target architecture) — recovery mechanics should build on that core, not on UI-layer snapshots. Orchestration and protocol surface are Go-side later.