Home app-side state in the shared App Group container

Every edition declares group.dev.rzen.indie.Kanban and homes its
app-side state there from day one (12-editions.md ruling 2026-07-29):

- AppGroup namespace: container resolution with per-edition fallback
  when unprovisioned, shared UserDefaults suite, edition identity, and
  a unit-test-host redirect (the test host IS the app — its launch
  sweep and recents refresh must not touch the real shared container).
- BoardRecord: bookmark/isOpenNow replaced by per-edition grants and
  openNow keyed by bundle id; hand-written Codable keeps legacy keys
  decoding (adopted in memory as the running edition's slots, upgraded
  on first save); every other field stays common.
- RecentBoard gains needsReopen: no grant of ours but somebody's —
  first click runs an open panel pre-anchored at the recorded path,
  prompt "Grant"; recordOpen mints this edition's slot onto the
  matched shared record (path fallback only after identity fails and
  only against records holding no grant of ours, so re-granting never
  forks the record).
- Cross-edition freshness: stat-cheap mtime+size stamp re-reads the
  registry when the sibling edition wrote it, so one edition's save
  never erases the other's records wholesale.
- restorables() filters on this edition's open-now flags; the board
  popover gains BoardEditionPresence ("Also open in Lanework Pro"),
  pid-liveness-checked so crash residue never lies.
- Clipboard staging store moves to the group container; the sweep
  claims doomed trees by atomic rename into .sweeping/ then deletes,
  so the sibling's concurrent sweep is a non-event.
- Template store re-homed to the group container per the 09-templates
  re-ruling; scalars (quick-style recents, window size) move to the
  shared suite.
- verify-editions.sh: 30 checks (each edition carries exactly the
  family group). No pathfinder 1.x migrator: 1.x predates the
  registry; state starts fresh in the group container.

Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY

KanbanTests/CardWindowShellTests.swift

@@ -43,7 +43,7 @@ private func subtitle(forCard cardID: String, boardNamed board: String, in model
     return CardWindowHost.subtitle(board: board, lane: placement.lane.title.value)
 }
 
-/// A registry whose file lives in temp rather than in the test host's Application Support.
+/// A registry whose file lives in temp rather than in the shared App Group container.
 @MainActor
 private struct RegistryStorage {
     let folder: URL
@@ -264,7 +264,10 @@ struct CardWindowIdentityTests {
         let storage = try RegistryStorage()
         defer { storage.tearDown() }
 
-        let model = AppModel(registryStorageURL: storage.url)
+        let model = AppModel(
+            registryStorageURL: storage.url,
+            clipboardStagingRoot: storage.folder.appendingPathComponent("Clipboard", isDirectory: true)
+        )
         let board = BoardWindowRef(url: fixture.root)
         let recordID = model.boardRegistry.recordOpen(of: fixture.root)
         let store = try model.storeRegistry.acquire(fixture.root)