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

Kanban/UI/Board/DragSession.swift

@@ -60,12 +60,11 @@ enum TrashDrop {
 
     /// The row the shadow takes, always: **the topmost**.
     ///
-    /// Not arbitrary, and the ranks are what make it honest: "every trash arrival mints a rank
-    /// above the current top" (04-interactions.md ▸ The trash), so a fresh delete genuinely lands on
-    /// top. The drop
-    /// therefore still lands exactly where the shadow shows — the one positional promise every other
-    /// drop in this app makes — while being the only proposal on the board the *pointer* does not
-    /// choose.
+    /// Not arbitrary, and the stamp is what makes it honest: "every trash arrival stamps `modified`
+    /// and the trash sorts newest-first by that stamp" (04-interactions.md ▸ The trash, re-ruled
+    /// 2026-07-31), so a fresh delete genuinely lands on top. The drop therefore still lands exactly
+    /// where the shadow shows — the one positional promise every other drop in this app makes —
+    /// while being the only proposal on the board the *pointer* does not choose.
     static let landingIndex = 0
 
     /// Whether the shown trash takes this session — the whole of the gate, and every clause is a
@@ -284,6 +283,18 @@ final class DragSession {
     /// and that is the whole of what makes it a restore (04-interactions.md ▸ The trash).
     private(set) var container: ItemContainer = .board
 
+    /// **Whether the selection this drag was picked up from spanned both kinds** — only ever true in
+    /// the trash, whose selection went kind-blind (04-interactions.md ▸ The trash, ruled 2026-07-31).
+    ///
+    /// A session carries items of exactly one `kind` — the pasteboard type is per-kind and a
+    /// `DragPayload` names one — so a mixed selection dragged from a trash row starts a session over
+    /// *its* kind and silently leaves the other behind. That silence is what this flag exists to
+    /// prevent: "pickup is allowed — the selection is legal — but every out-of-trash drop target
+    /// refuses the mixed payload, and the release surfaces a notice explaining the rule". The refusal
+    /// is at the commit (`BoardDropContext.commitDrop`), where every drop out of the trash funnels,
+    /// rather than at hover — 04 puts the explanation at the release.
+    private(set) var mixesKinds = false
+
     /// The dragged items in **flatten order** — the order they will land in.
     private(set) var members: [ItemID] = []
 
@@ -496,16 +507,33 @@ final class DragSession {
         folders: [URL],
         heights: [CGFloat],
         container: ItemContainer,
-        source: BoardStore
+        source: BoardStore,
+        mixesKinds: Bool = false
     ) {
-        begin(kind: .cards, members: members, folders: folders, container: container, source: source)
+        begin(
+            kind: .cards, members: members, folders: folders,
+            container: container, source: source, mixesKinds: mixesKinds
+        )
         cardHeights = heights
         laneUnits = []
     }
 
     /// Begins a lane session.
-    func beginLanes(_ members: [ItemID], folders: [URL], units: [Int], source: BoardStore) {
-        begin(kind: .lanes, members: members, folders: folders, container: .board, source: source)
+    ///
+    /// `container` is a parameter because a **trashed lane row**'s drag is a `.lanes` session in
+    /// `.trash` — the restore at the lane level (04-interactions.md ▸ The trash ▸ Drag-to-restore).
+    func beginLanes(
+        _ members: [ItemID],
+        folders: [URL],
+        units: [Int],
+        container: ItemContainer = .board,
+        source: BoardStore,
+        mixesKinds: Bool = false
+    ) {
+        begin(
+            kind: .lanes, members: members, folders: folders,
+            container: container, source: source, mixesKinds: mixesKinds
+        )
         laneUnits = units
         cardHeights = []
     }
@@ -515,7 +543,8 @@ final class DragSession {
         members: [ItemID],
         folders: [URL],
         container: ItemContainer,
-        source: BoardStore
+        source: BoardStore,
+        mixesKinds: Bool
     ) {
         endHold()
         self.kind = kind
@@ -523,6 +552,7 @@ final class DragSession {
         self.memberSet = Set(members)
         self.folders = folders
         self.container = container
+        self.mixesKinds = mixesKinds
         self.sourceStore = source
         self.sourceRoot = source.rootURL
         self.proposal = nil