Remove the App Group wholesale — one sandbox, one bookmark, one flag

Phase 2 of the one-app pivot (DESIGN 12 ▸ App-side state, re-ruled
2026-07-30; reworks 566deab). AppGroup retires; what remains is
AppStateHome — ordinary sandbox Application Support as the one home for
the registry, clipboard staging and template stores, keeping the
unit-test-host redirect (the test host is the app and would sweep real
state). Scalar defaults return to UserDefaults.standard.

BoardRecord's per-edition grant slots and openNow flags collapse to one
bookmark + one isOpenNow; the legacy-key decode and adopt-in-memory
paths go (nothing shipped with group-era records), while the founding
four-keys-required / defaults-for-everything-since decode policy stays —
a bookmarkless record decodes as the born-orphan row rather than
quarantining the list. needsReopen and the pre-anchored re-grant panel
are removed whole: the only state that flow served — a record granted by
a sibling sandbox — is unrepresentable now, and a dead bookmark of our
own was already the orphan case by explicit comment. The
indexOfRecord path fallback dies with it; path is never a key again.

The cross-process freshness stamp (mtime+size re-read) and
BoardEditionPresence with its popover "Also open in…" line retire; the
clipboard prune keeps its atomic .sweeping/ claim-then-delete, reframed
for crash residue and open -n copies rather than sibling editions. The
application-groups entitlement key is gone.

1880 tests in 317 suites green (13 cross-edition tests retired with
their subject).

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

Kanban/App/UITestLaunch.swift

@@ -90,18 +90,15 @@ enum LaunchPlan: Equatable, Sendable {
 /// Without that, every audit run would stamp a temp folder into the user's real recents list
 /// (`BoardRegistry.defaultStorageURL`), where it would sit for good as an unavailable row pointing at a
 /// directory that no longer exists — and its launch sweep would collect the user's real staged copy
-/// (`ClipboardStore.defaultStagingRoot`). Both of those homes are now the **shared App Group
-/// container** (12-editions.md ▸ Distribution, ruled 2026-07-29), so each of those side effects would
-/// land on the sibling edition as well as this one. Tying them to the same flag rather than to separate
+/// (`ClipboardStore.defaultStagingRoot`). Tying them to the same flag rather than to separate
 /// arguments is deliberate: they are one decision — "this launch is synthetic" — and a second argument
 /// is a second chance to apply only half of it.
 ///
 /// The honest residual: `UserDefaults` is **not** redirected, so an audit run can still write the
-/// three app-wide scalars (`AppPreferences`) into the real domain — the group's shared suite since the
-/// same ruling. They are a window size, a restore toggle this launch never consults, and the
-/// quick-style recents list — no documents, nothing destructive, and redirecting a defaults domain from
-/// inside the process is not something the platform actually supports. It is stated rather than
-/// fixed.
+/// three app-wide scalars (`AppPreferences`) into the real domain. They are a window size, a restore
+/// toggle this launch never consults, and the quick-style recents list — no documents, nothing
+/// destructive, and redirecting a defaults domain from inside the process is not something the
+/// platform actually supports. It is stated rather than fixed.
 enum UITestLaunch {
 
     private static let logger = Logger(subsystem: "dev.rzen.indie.Kanban", category: "ui-test-launch")
@@ -206,17 +203,15 @@ enum UITestLaunch {
             .appendingPathComponent("LaneworkUITestFixture", isDirectory: true)
     }
 
-    /// Where the fixture launch's registry lives — beside the board rather than in the shared App
-    /// Group container, which is the whole point (see the type's note).
+    /// Where the fixture launch's registry lives — beside the board rather than in Application
+    /// Support, which is the whole point (see the type's note).
     static var registryStorageURL: URL {
         scratchRoot.appendingPathComponent("board-registry.json", isDirectory: false)
     }
 
-    /// Where the fixture launch's clipboard snapshots live, on the registry's terms and now for a
-    /// sharper reason: the real staging root moved into the **shared** App Group container
-    /// (12-editions.md ▸ Both editions installed), so an audit run's launch sweep would otherwise
-    /// collect the developer's own staged copy — and the sibling edition's, since there is only one
-    /// store now. Redirected by the same flag, because it is the same one decision.
+    /// Where the fixture launch's clipboard snapshots live, on the registry's terms: an audit run's
+    /// launch sweep would otherwise collect the developer's own staged copy. Redirected by the same
+    /// flag, because it is the same one decision.
     static var clipboardStagingRoot: URL {
         scratchRoot.appendingPathComponent("Clipboard", isDirectory: true)
     }