Heal commits are transparent to undo — the bounce is bounded to one, post-relaunch only

Ruled 2026-07-29: heal-class commits (known in-session by heal-marked EchoLedger receipts) never become undo steps — the stack pointer passes over them and restores exclude heal-owned paths, so ⌘Z never reverts a repair and never re-arms the scheduler; naive acceptance would trap a ⌘Z run on an ever-renewing heal commit, and suppression would create standing invalid states. Post-relaunch reseed stays sidecar-free, so old heal commits bounce once — restore plus fresh heal commit, the fresh one transparent, the run continuing past it. Accepted family-wide; the agent-guide quirk becomes the rule's oldest case.

Board: Gap card b444bc5c → Resolved. Pro-era implementation (pro-m1).

Claude-Session: https://claude.ai/code/session_01CqjXB7ASoWtbyoGod68k97

DESIGN/06-history-undo.md

@@ -18,6 +18,7 @@ Git is the undo substrate — on boards that have git. **Git is opt-in per board
 - **Undo restore vs open Edit sessions** (settled): a restore materializes only the diff between the current tree and the target state, so a card whose open Edit session the diff doesn't touch is simply unaffected — its uncommitted ~700 ms saves and the stage-around rule continue undisturbed, and most undos never meet an editor at all. When the diff *does* touch a session card, the restore **gates on the branch-switch save-or-discard step** (Branch switching below — Save All / Discard / Cancel, same machinery, same rationale): silently flushing would commit a tree the user deliberately hasn't saved, a checkout over uncommitted on-disk saves would destroy text no commit protects (the one place "both versions exist as commits" could otherwise fail), and a surviving dirty buffer's next debounced save would write pre-undo text over the restored card — a ⌘Z that visibly doesn't happen. With sessions settled the restore runs on a settled tree. Redo is symmetric. Open raw-source buffers get the branch-switch settle treatment too (Branch switching below).
 - **The stack is HEAD's first-parent ancestry, live** (settled): foreign commits — watcher-auto-committed agent work and agents' *self*-commits alike — push onto the in-session undo stack as ordinary steps as they land. The stack re-syncs its top to HEAD before every undo/redo (self-commits move HEAD outside the app's committer; the pre-flight sync is how the stack learns), so ⌘Z always steps back exactly **one** commit — it can never silently revert twenty minutes of agent work landed since the user's last operation. Any commit arriving from anywhere clears the redo stack (classic behavior; redo also starts empty on the relaunch reseed below). In-session and post-relaunch behavior are thereby one rule — the reseed is the same ancestry walk from scratch.
 - **Undo survives relaunch**: the undo stack reseeds from HEAD's first-parent ancestry on load; redo starts empty. In-session it behaves as classic dual stacks; after relaunch, past restore commits reappear as ordinary undoable steps. Deliberate: no sidecar state, nothing ever lost. Interaction with pull (07-sync-collab.md): a pull rebases unpushed local commits, so the in-session stack must remap onto the rewritten commits — the pre-rebase hashes are orphaned. A pleasant consequence of the reseed rule: the fetched remote commits sit in HEAD's first-parent ancestry, so after the next relaunch remote work becomes ordinary undoable steps too.
+- **Heal commits are transparent to undo, in-session** (ruled 2026-07-29): heal-class commits — their paths known by the Writer's heal-marked receipts (Commit messages below) — never become undo steps: the stack pointer passes over them, and a restore materializing an older target **excludes paths whose divergence is heal work**, so a ⌘Z run never reverts a repair and never summons the scheduler (reverting one would re-arm the memo on the recreated defect signature, land a fresh heal commit, and — redo cleared — trap the run on an ever-renewing top; transparency dissolves the trap instead of suppressing the healer). The in-session qualifier is honest: receipts live in memory and the reseed is deliberately sidecar-free, so after relaunch old heal commits reappear as ordinary steps — undoing one recreates its defect and the scheduler re-heals within a reload, restore commit plus fresh heal commit, notice included. That **residual bounce is accepted family-wide** — the agent-guide quirk (Agent collaboration below) generalized to the relocation, the legacy migration, the displacement, and the remint — and it is **self-limiting to one bounce**: the fresh heal commit is in-session, transparent, and the undo run continues past it. Redo is symmetric.
 - **Undo is board-local.** A cross-board move-out undone at the source resurrects the card even though it lives on in the destination — per-board histories cannot and must not mutate other boards. The resulting same-UUID fork across boards is legitimate (boards are independent identity namespaces); if the two ever meet through a move-in, the import boundary remints the arrival (01-storage-format.md's identity lifecycle).
 - The git surface lives in the **board popover** (03-board-ui.md): branch/source display, branch switching and creation, and the commit-identity name/email fields (see Interaction with external writers below) — alongside board rename and styling.
 
@@ -53,7 +54,7 @@ Switching (or creating-and-switching) a branch from the board popover:
 
 ## Interaction with external writers
 
-Agent and hand edits arrive through the watcher like any change and get auto-committed on the same debounce — so agent work is undoable, attributed, and *described* in the same trail: foreign changes compose through the same message engine as app-mediated ones (Commit messages above — the pathfinder's generic "External edit: 2 cards changed" fallback is gone), with origin carried by the author field. One attribution exception: the app's own agent-guide writes (08-agent-integration.md) are the app's own Writer operations — app-mediated by the echo machinery, carrying the guide's version-marker first line — and committed as "Update agent guide (vN)", not "External edit". Known quirk, not a bug: undoing an "Update agent guide (vN)" commit restores an older guide that the app immediately re-upgrades — a one-bounce no-op undo (restore commit + fresh upgrade commit). Harmless; the guide is app-owned and self-healing by design.
+Agent and hand edits arrive through the watcher like any change and get auto-committed on the same debounce — so agent work is undoable, attributed, and *described* in the same trail: foreign changes compose through the same message engine as app-mediated ones (Commit messages above — the pathfinder's generic "External edit: 2 cards changed" fallback is gone), with origin carried by the author field. One attribution exception: the app's own agent-guide writes (08-agent-integration.md) are the app's own Writer operations — app-mediated by the echo machinery, carrying the guide's version-marker first line — and committed as "Update agent guide (vN)", not "External edit". The guide-commit undo quirk is the heal-transparency rule's oldest case (Rules ▸ Heal commits are transparent): in-session the upgrade commit never enters the stack; only a relaunch-old guide commit bounces — once, restore commit plus fresh upgrade commit, the fresh one transparent. Harmless; the guide is app-owned and self-healing by design.
 
 **Commit attribution is structural, not just a message convention.** The Writer/echo machinery (the **EchoLedger** — 02-architecture.md ▸ Components, where its matching rule and race cases are settled) lets the auto-committer classify every observed change, per file, as **app-mediated** (the user acting through the app) or **foreign** (anything else). User-driven commits carry the user's git identity; foreign changes are committed under the pinned synthetic author **`Lanework External <[email protected]>`** — so any git client can filter, log, and blame by origin. The strings are API (users script against them; the `.invalid` TLD honestly marks a non-routable synthetic identity) — they change with the deliberateness of a schema change.