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/StyleWriteTests.swift

@@ -54,9 +54,9 @@ private func makeBoard() throws -> WriterFixture {
     try fixture.item("\(Ident.lane1)/\(Ident.card1)", styled(order: "1024", title: "First", keys: ["background: fern", "iconColor: chalk"]))
     try fixture.item("\(Ident.lane1)/\(Ident.card2)", styled(order: "2048", title: "Second"))
     try fixture.item(Ident.lane2, styled(order: "2048", title: "Doing", keys: ["background: chalk", "icon: tray"]))
-    try fixture.item("\(Ident.lane2)/\(Ident.card3)", styled(order: "1024", title: "Third", keys: ["deleted: 2026-03-03T09:00:00Z"]))
+    try fixture.item("\(Ident.lane2)/\(Ident.card3)", styled(order: "1024", title: "Third"))
     try fixture.item(Ident.lane3, Item.uneditable)
-    try fixture.item(Ident.lane4, styled(order: "4096", title: "Gone", keys: ["deleted: 2026-03-03T09:00:00Z"]))
+    try fixture.item(Ident.lane4, styled(order: "4096", title: "Gone"))
     try fixture.item("\(Ident.lane4)/\(Ident.card4)", styled(order: "1024", title: "Hidden"))
     return fixture
 }
@@ -256,26 +256,27 @@ struct StyleWriteTests {
         #expect(lane(lane1, in: model)?.background.isMissing == true)
     }
 
-    @Test("Vanished, tombstoned and hidden targets are skipped silently")
+    @Test("Vanished and trashed targets are skipped silently")
     func skipsTargetsThatRenderNowhere() throws {
         let fixture = try makeBoard()
         defer { fixture.tearDown() }
+        try fixture.move("\(Ident.lane2)/\(Ident.card3)", toTrash: Ident.card3)
+        try FileManager.default.removeItem(at: fixture.url(Ident.lane4))
         let store = try BoardStore(rootURL: fixture.root)
         let log = BracketLog()
         log.attach(to: store)
-        let tombstoned = try fixture.indexData("\(Ident.lane2)/\(Ident.card3)")
-        let hidden = try fixture.indexData("\(Ident.lane4)/\(Ident.card4)")
+        let trashedBytes = try fixture.indexData(".trash/\(Ident.card3)")
 
-        // An id that names nothing, a tombstoned card, and a live card under a tombstoned lane —
-        // "nothing is ever written into a vanished folder", ancestor walk included.
+        // An id that names nothing, and a card that has been moved to the trash — "everything
+        // edit-shaped is disabled on trash selections" (04 ▸ The trash), and "nothing is ever
+        // written into a vanished folder".
         store.applyStyle(
             to: .items([ItemID(rawValue: Ident.indexless), card3, card4]),
             background: .set("obsidian")
         )
 
         #expect(log.begins == 0)
-        #expect(try fixture.indexData("\(Ident.lane2)/\(Ident.card3)") == tombstoned)
-        #expect(try fixture.indexData("\(Ident.lane4)/\(Ident.card4)") == hidden)
+        #expect(try fixture.indexData(".trash/\(Ident.card3)") == trashedBytes)
         #expect(store.banners.oneShots.isEmpty)
     }
 
@@ -314,13 +315,13 @@ struct StyleWriteTests {
 
     // MARK: Subjects and levels
 
-    @Test("Subjects are the live targets in display order, with their current values")
-    func subjectsAreLiveTargetsInDisplayOrder() throws {
+    @Test("Subjects are the board's targets in display order, with their current values")
+    func subjectsAreBoardTargetsInDisplayOrder() throws {
         let fixture = try makeBoard()
         defer { fixture.tearDown() }
         let store = try BoardStore(rootURL: fixture.root)
 
-        let subjects = store.styleSubjects(of: .items([card2, card1, card3, lane1]))
+        let subjects = store.styleSubjects(of: .items([card2, card1, lane1]))
         #expect(subjects.map(\.id) == [lane1, card1, card2], "lane first, then its cards top to bottom")
         #expect(subjects.map(\.background) == [.missing, .valid("fern"), .missing])
         #expect(subjects.last?.folder.lastPathComponent == Ident.card2)