diff --git a/DESIGN/02-architecture.md b/DESIGN/02-architecture.md
index fdf9e63..bf371ca 100644
--- a/DESIGN/02-architecture.md
+++ b/DESIGN/02-architecture.md
@@ -29,7 +29,7 @@ The **one named exception** is transient UI state rendering things that don't ex
 - **Frontmatter** — YAML value model: parse, serialize, atomic write, unknown-key preservation with key order. Owns the byte-identical round-trip guarantee. Pure, heavily unit-tested.
 - **BoardLoader** — walks the folder tree, applies the fail-fast/skip rules, produces an immutable `BoardModel` snapshot. Pure function of the tree.
 - **BoardWriter** — every mutation (create, move, reorder, tombstone, style) as an explicit filesystem operation. No hidden state; a write is done when the file is on disk.
-- **BoardStore** — per-board `@Observable` object holding the current snapshot plus transient UI state that must be shared across that board's windows (selection, drag state, search query, pending cut, the new-card placeholder, trash visibility). Debounces watcher reloads.
+- **BoardStore** — per-board `@Observable` object holding the current snapshot plus transient UI state that must be shared across that board's windows (selection, drag state, search query, pending cut, the new-card placeholder, trash visibility). Coalesces watcher reloads — at most one tree walk in flight, signals landing mid-walk fold into one follow-up; the debounce itself lives in FolderWatcher (above).
 - **BoardStoreRegistry** — refcounted registry so a board window and its card windows share one live store and one watcher. **The board window owns the board** (settled): card windows never outlive it — closing the board window closes its card windows too, so the last-window teardown and board-window close coincide. (The refcount still earns its keep ordering teardown while multiple windows close.)
 - **FolderWatcher** — FSEvents (debounced: **200 ms trailing**, the timer restarting per event so a burst yields one reload after quiet, over 50 ms FSEvents latency — settled numbers), attached best-effort to whatever path the board lives at. **Events under any `.git` path component are filtered out** (settled): the board's own root-level repo (a worktree-link `.git` file included) is the app's auto-commit churn, and a repo nested deeper — a card folder containing a clone, a submodule — is a stray (01-storage-format.md) whose internals never render; neither can alter the rendered tree, so neither drives reloads. (A nested repo's *working files* still fire events like any stray's — those reloads are value-equal and quiet.) There is only this one watching path: no NSMetadataQuery for iCloud Drive, no polling fallback for network volumes — on those warned-against locations (07-sync-collab.md) FSEvents delivery is unreliable and live reload silently degrades, accepted per 07's no-accommodations stance.
 - **Ranks** — gapped fractional ordering math + compaction. Pure.
@@ -42,7 +42,7 @@ The **one named exception** is transient UI state rendering things that don't ex
 - **A failed reload never replaces a good snapshot.** Fail-fast (01-storage-format.md) is the *initial-load* contract, where there is nothing to fall back on. Once a board is open, a watcher-triggered reload that fails (unparseable YAML, missing required fields — typically a non-atomic external write caught mid-flight) keeps the last good snapshot on screen and raises a **non-modal banner** carrying fail-fast's specifics (offending path + what's wrong). The watcher keeps watching; the next successful reload clears the banner automatically — transient breakage self-heals without the user losing the board, persistent breakage stays loudly visible. Editing is not locked out: writes go through the Writer as usual (the breakage is per-file and localized), and the reload debounce already absorbs most momentary invalid states before they surface.
 - **The watcher is self-reconciling, never trusted blindly** (settled): every reload is already a full tree walk producing a value-type snapshot, so recovery from any blind window is always the same act — reload. A **reconciling reload** runs on wake-from-sleep and on app re-activation (debounced; an identical tree swaps in value-equal, so quiet reconciliations cost nothing visible), on any FSEvents flag admitting missed events (`MustScanSubDirs`, queue overflow — degrade to the reload rather than trust the gap), and after any stream re-creation. **Streams die and are recreated, not merely kept**: a volume unmount kills the stream with its root; the vanished-root and rename re-resolution rules (below) attach a *fresh* stream at the current root when it returns, reconciling reload included. A silently stale board — the worst failure for a files-are-truth app — is structurally excluded: every known blind window ends in a reload. **A reconcile request arriving mid-bracket is banked** (settled): the mandatory post-bracket reload delivers as the *reconciling* kind rather than app-mediated — an explicit reconciliation is never silently lost. FSEvents missed-events flags arriving mid-bracket are, by contrast, simply swallowed: the post-bracket reload is a full walk either way, and only the origin tag differs (it feeds commit attribution and the VoiceOver announcement vocabulary — a deliberate asymmetry).
 - **App-initiated git churn is bracketed.** Operations the app runs itself (pull-rebase, branch switch, undo restore — 06-history-undo.md, 07-sync-collab.md) suspend watcher reloads for their duration and finish with one full reload — half-checked-out trees are never rendered. **The bracket also locks writes** (settled): for its duration the board is read-only with exactly the failed-reload lock's scope — mutating commands disable via menu validation, drops are refused, selection/navigation/search/copy-out stay live. 07's interaction-rest rule composes: the bracket starts only at gesture rest, so nothing in flight is interrupted; the lock ends with the final reload — seconds, honestly signaled by the operation's in-progress banner row (▸ The banner surface). External git activity (the user running git in a terminal) can't be bracketed: the debounce coalesces its churn, and a transiently inconsistent but parseable tree may render briefly and heals on the next event — accepted.
-- **Selection survives reloads by UUID.** Selection — and every transient state that references items (drag state, pending cut) — is a set of UUIDs over the snapshot, re-resolved when a reload swaps it: items still present stay selected; items that vanished leave the selection silently, no substitute invented — the search filter's hidden-cards-leave-the-selection rule (04-interactions.md) applied to external change. **A liveness flip is a vanish for this purpose**: re-resolution matches UUID *and* liveness side, so a foreign edit that tombstones a selected live card — or restores a selected tombstoned one — ejects it from the selection (and from the pending cut, which 04-interactions.md ▸ Clipboard already states), keeping 04's homogeneous-by-liveness invariant true across reloads. The search filter is deliberately absent from that list: the query string is transient state, but its result set is *derived* — the predicate re-runs against each new snapshot (04's live filter), so a card an agent files mid-search appears the moment the reload lands, and a card edited to no longer match animates out. Kin rules elsewhere: card windows dismiss when their card is deleted (05-card-window.md), the placeholder is discarded when its lane vanishes (above), and VoiceOver announces a vanished focused card and recovers focus to its lane (10-accessibility.md). App-mediated deletion is deliberately different — an act, not a surprise: ⌫ selects the successor sibling (04-interactions.md ▸ The map).
+- **Selection survives reloads by UUID.** Selection — and every transient state that references items (drag state, pending cut) — is a set of UUIDs over the snapshot, re-resolved when a reload swaps it: items still present stay selected; items that vanished leave the selection silently, no substitute invented — the search filter's hidden-cards-leave-the-selection rule (04-interactions.md) applied to external change. **A liveness flip is a vanish for this purpose**: re-resolution matches UUID *and* liveness side, so a foreign edit that tombstones a selected live card — or restores a selected tombstoned one — ejects it from the selection (and from the pending cut, which 04-interactions.md ▸ Clipboard already states), keeping 04's homogeneous-by-liveness invariant true across reloads. **Liveness here is effective — ancestor-walked** (settled): tombstoning a card's *lane* ejects the card too, its own flag notwithstanding — the card renders nowhere (03-board-ui.md collapses a tombstoned lane to a single restorable trash entry), and nothing invisible may stay selected, drag-included, or pending-cut. The search filter is deliberately absent from that list: the query string is transient state, but its result set is *derived* — the predicate re-runs against each new snapshot (04's live filter), so a card an agent files mid-search appears the moment the reload lands, and a card edited to no longer match animates out. Kin rules elsewhere: card windows dismiss when their card is deleted (05-card-window.md), the placeholder is discarded when its lane vanishes (above), and VoiceOver announces a vanished focused card and recovers focus to its lane (10-accessibility.md). App-mediated deletion is deliberately different — an act, not a surprise: ⌫ selects the successor sibling (04-interactions.md ▸ The map).
 - **A failed reload after a bracketed operation locks the board read-only** — the exception to "editing is not locked out" above. Ordinary watcher breakage is per-file: the snapshot still describes the tree, so editing around the broken file is safe. But a bracketed git operation changed the tree *wholesale*: if its final reload fails, the last-good snapshot on screen describes the pre-operation state (after a branch switch, a different branch entirely — 06-history-undo.md), and writes derived from it would land nonsense on the new tree. The banner carries the same fail-fast specifics plus the read-only state; the next successful reload (typically after the offending file is fixed) clears both. **The rule arms on every bracket exit, thrown operations included** (settled): an operation that fails or aborts mid-flight is precisely when the tree's state is least known, so the mandatory final reload runs regardless — succeeding, it renders whatever the operation left (often value-equal after a clean failure, whose tree is left as it was — 06-history-undo.md); failing, it locks exactly as above. **The lock's scope** (shared with the vanished-root case below) spans every window sharing the store — card windows included: every mutating command disables via menu validation — creation, delete and Put Back, paste, Move/Style/rename, trash operations, the popover's git controls, and the card window's write paths: the flip into Edit mode, raw-source entry and Apply, Add Attachment and the whole-window file drop, the sidebar's mutating actions, and task-list checkbox toggles — and the board refuses drops, including drags arriving from another board's window. Drags *out* of a locked board offer the copy variant only — copy-out is a read; a ⌘-drag move's source-side delete is a write, so the modifier doesn't take. **An Edit buffer already open when the lock lands keeps its content and stays typable** — memory is not disk — but its debounced save suspends for the lock's duration; the held text's fate follows the lock's cause: a branch switch or undo restore can't leave a session open behind the lock at all (both settle editors first — 06-history-undo.md), a post-pull buffer saves on clear and wins per the sync model (05-card-window.md, 07-sync-collab.md), and a returned root saves normally (below). Selection, navigation, search, ⌘C copy-out, and Reveal in Finder stay live (reading the last-good snapshot is the point of keeping it).
 
 ### Write-failure surfacing