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

KanbanTests/InlineEditWriteTests.swift

@@ -220,21 +220,21 @@ struct InlineRenameWriteTests {
         #expect(store.banners.oneShots.isEmpty)
     }
 
-    @Test("A commit at a card under a tombstoned lane writes nothing — liveness is effective")
-    func targetUnderATombstonedLaneWritesNothing() throws {
+    @Test("A commit at a card that entered the trash writes nothing")
+    func targetInTheTrashWritesNothing() throws {
         let fixture = try makeBoard()
         defer { fixture.tearDown() }
-        // The lane carries the tombstone; the card's own flag is untouched, and it renders nowhere
-        // regardless (03-board-ui.md collapses the lane to one trash entry).
-        try fixture.item(Ident.lane1, tombstoned(order: "1024", title: "Todo"))
+        // "Entering the trash is a vanish from the board; nothing is ever written into a vanished
+        // folder" (04 ▸ Grammar).
+        try fixture.move("\(Ident.lane1)/\(Ident.card1)", toTrash: Ident.card1)
         let store = try BoardStore(rootURL: fixture.root)
-        let before = try fixture.indexData("\(Ident.lane1)/\(Ident.card1)")
+        let before = try fixture.indexData(".trash/\(Ident.card1)")
 
         store.transient.beginRename(of: card1, currentTitle: "First")
         store.transient.updateRenameDraft("Never lands")
         store.commitRename()
 
-        #expect(try fixture.indexData("\(Ident.lane1)/\(Ident.card1)") == before)
+        #expect(try fixture.indexData(".trash/\(Ident.card1)") == before)
         #expect(store.banners.oneShots.isEmpty)
     }