Materialize the trash — store, undo, and the container universe

Phase 2 swaps every consumer: Liveness and its ancestor walk are gone,
replaced by ItemContainer — a UUID set plus the container side it
lives on, presence the whole test, one selection boundary instead of
the old liveness law. Deletion stages by place: board cards move to
the trash at a store-minted head rank, trash-side delete is permanent
behind its confirmation, Delete Immediately skips the trash from
anywhere, lane delete captures the subtree and removes the folder.
Restore has no method at all — moveCards resolves members in either
container, so drag-out and cut-paste are the ordinary moves 13 calls
them, registering ordinary Move steps. The delete inverse moves the
card back to its captured lane and rank; redo replays the captured
trash rank, a value the gesture actually wrote; lane undo recreates
the subtree byte-faithfully in session. Purges register nothing —
where 13's trash section contradicts its own Rules on that, Rules
wins, filed for ruling. Staleness collapsed to present-or-absent: a
container is a path, so a foreign restore fails the delete step's
expectation structurally. Legacy tombstones migrate on the loose-file
tail hook, cards oldest-first so minting above top reproduces the
retired newest-first column, lanes returning live, one folded loss
row naming both directions. Put Back, restoreByDrag,
receiveRestoredCards, TrashEntry, and the kind machinery are deleted;
the trash column renders the container correctly with its full face
rework left to phase 3.

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

Kanban/App/CardWindowHost.swift

@@ -175,9 +175,7 @@ struct CardWindowHost: View {
         let identity = ItemID(rawValue: cardID)
         for lane in snapshot.lanes {
             guard let card = lane.cards.first(where: { $0.id == identity }) else { continue }
-            return lane.isDeleted || card.isDeleted
-                ? .dismisses
-                : .shows(CardPlacement(card: card, lane: lane))
+            return .shows(CardPlacement(card: card, lane: lane))
         }
         return .dismisses
     }
@@ -319,7 +317,7 @@ struct CardWindowHost: View {
     /// links resolve against (05-card-window.md ▸ Preview).
     ///
     /// Built off the store's *current* `rootURL` rather than the ref's captured one, for
-    /// `BoardStore.liveItem`'s reason: a mid-session folder rename moves the board, and a preview
+    /// `BoardStore.boardItem`'s reason: a mid-session folder rename moves the board, and a preview
     /// resolving images against where the board used to be would quietly stop showing them.
     static func cardFolder(root: URL, placement: CardPlacement) -> URL {
         root