Realign code with the 2026-07-31 rulings

The trash sorts by modified descending — the arrival rank mint retires
(Ranks.isOrderedForTrash one comparator, loader + merged order agree;
the legacy deleted: migration stamps modified from the tombstone
timestamp where parseable; delete undo steps validate existence-only;
agent guide v8). Trash selection goes kind-blind — ranges, marquee,
Select All, and the successor walk sweep both kinds; the guard moves to
the exits (mixed-payload drop refusal, copy/cut validation). The copy
stamping preflight widens back to comment depth (load-scoped posture —
the board always loads, the gesture refuses whole). Fixes a latent
no-op: trashed-lane drag restore never fired (DragSession.beginLanes
hard-coded the board container).

2403 tests in 413 suites green.

Claude-Session: https://claude.ai/code/session_01CqjXB7ASoWtbyoGod68k97

KanbanTests/DragWriteTests.swift

@@ -675,9 +675,14 @@ struct RestoreByMoveOutTests {
         try fixture.item("\(Ident.lane1)/\(Ident.card1)", Item.rich(order: "1024", title: "First"))
         try fixture.item(Ident.lane2, Item.rich(order: "2048", title: "Doing"))
         try fixture.item("\(Ident.lane2)/\(Ident.card4)", Item.rich(order: "1024", title: "Fourth"))
-        // The trash's own order is its display order — `card3` above `card2`, newest-first.
-        try fixture.item(".trash/\(Ident.card2)", Item.rich(order: "2048", title: "TrashedA"))
-        try fixture.item(".trash/\(Ident.card3)", Item.rich(order: "1024", title: "TrashedB"))
+        // The trash's own order is its display order, and since 2026-07-31 that is `modified`
+        // descending (01-storage-format.md § Deletion) — `card3` above `card2`, newest-first.
+        try fixture.item(
+            ".trash/\(Ident.card2)",
+            "---\nschema: 1\ntitle: TrashedA\norder: 2048\nmodified: 2026-05-01T09:00:00Z\n---\n")
+        try fixture.item(
+            ".trash/\(Ident.card3)",
+            "---\nschema: 1\ntitle: TrashedB\norder: 1024\nmodified: 2026-05-03T09:00:00Z\n---\n")
         let store = try BoardStore(rootURL: fixture.root)
 
         store.moveCards([card3, card2], toLane: lane2, at: 0)
@@ -829,7 +834,7 @@ struct RestoreLaneTests {
         #expect(try fixture.indexText(Ident.lane3).contains("project: lanework"), "unknown keys ride along")
     }
 
-    @Test("Its undo is the ordinary move back in, at the trash rank the row was holding")
+    @Test("Its undo is the ordinary move back in, at the `order` the row was carrying")
     func undoMovesItBackIn() throws {
         let fixture = try makeTrashedLaneBoard()
         defer { fixture.tearDown() }