Selection liveness is effective — ancestor-walked (ratified)

The parallel design session settled the tombstoned-ancestor question:
a card counts as trashed if its own flag or its lane's says so, so
tombstoning a lane ejects its cards from a live selection — they render
nowhere once the lane collapses to a single trash entry, and nothing
invisible may stay selected, drag-included, or pending-cut. One-line
predicate change in Selection.resolved(against:), plus the test.

Full BoardStore suite green (15 tests).

Claude-Session: https://claude.ai/code/session_018BjQRYBR6jQja3jCRi5S3A

Kanban/LiveStore/BoardStore.swift

@@ -100,9 +100,11 @@ public struct Selection: Sendable, Equatable {
     ///   homogeneous-by-liveness invariant true across reloads so menu validation never sees a
     ///   mixed selection.
     ///
-    /// The match is on the item's *own* tombstone flag. A live card sitting under a tombstoned lane
-    /// therefore survives re-resolution even though the board does not render it — the loader keeps
-    /// it in the snapshot, and "still present, same side" is the rule as written.
+    /// The liveness that is matched is **effective — ancestor-walked** (settled): a card counts as
+    /// trashed if its own flag *or its lane's* says so. Tombstoning a lane therefore ejects its
+    /// cards from a live selection even though their own flags never changed — the card renders
+    /// nowhere once 03-board-ui.md collapses the lane to a single trash entry, and nothing
+    /// invisible may stay selected, drag-included, or pending-cut.
     public func resolved(against snapshot: BoardModel) -> Selection {
         guard !ids.isEmpty else { return self }
 
@@ -113,7 +115,7 @@ public struct Selection: Sendable, Equatable {
                 survivors.insert(lane.id)
             }
             for card in lane.cards where ids.contains(card.id) {
-                if Liveness(isDeleted: card.isDeleted) == liveness {
+                if Liveness(isDeleted: lane.isDeleted || card.isDeleted) == liveness {
                     survivors.insert(card.id)
                 }
             }