Realign code with the 2026-07-30 findings-resolution rulings

Delete Immediately is removed entirely (ruling ae1dd96, Redesign card
d40bfac1): the delete vocabulary is purely staged — board → trash,
trash → permanent (confirmed on no-git boards), Empty Trash for bulk.
Gone: File ▸ Delete Immediately (⌥⌘⌫) and its validation, both
⌥-alternate context rows (card + the permanently-disabled lane row),
the VO custom action, BoardStore.deleteImmediately,
TrashModel.canDeleteImmediately, TrashConfirmations' .purge action
(zero surviving callers — trash-side Delete always used
.deleteTrashCards), and the pinning tests. purgePrompt drops its
now-single-purpose container parameter (.trash is the only surviving
caller). BoardWriter.purgeItem survives — create-undo rollback still
needs it — with its comment rewritten. README's trash paragraph drops
the ⌥⌘⌫ sentence.

The other 2026-07-30 rulings (2ec2c95 registry freshness stamp,
c741b02 unified-log-as-coerce-consumer) required no code changes —
already conformant.

Both schemes 1844 tests / 318 suites green.

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

Kanban/Storage/BoardWriter.swift

@@ -1248,12 +1248,12 @@ public enum BoardWriter: Sendable {
         EchoLedger.current?.recordDeletion(at: laneFolder)
     }
 
-    /// Permanently removes one card from the trash — the trash's **Delete / Delete Immediately**
+    /// Permanently removes one card from the trash — the trash's own **Delete**
     /// (03-board-ui.md § Trash: "on a trash card, Delete (⌫/⌘⌫) is permanent").
     ///
     /// `purgeItem` with the container checked: the folder must actually sit in this board's
-    /// `.trash/`, so a mis-aimed permanent delete cannot reach a live card. Delete Immediately
-    /// *from* the board — which skips the trash — is `purgeItem`, not this call.
+    /// `.trash/`, so a mis-aimed permanent delete cannot reach a live card. `purgeItem`
+    /// (unconstrained) is for the create-undo's own removal, not this call.
     ///
     /// An already-gone folder is success, `purgeItem`'s rule.
     public static func purgeTrashCard(at cardFolder: URL, inBoard boardRoot: URL) throws(BoardWriteError) {
@@ -1536,10 +1536,10 @@ public enum BoardWriter: Sendable {
         try? FileManager.default.setAttributes([.posixPermissions: permissions], ofItemAtPath: url.path)
     }
 
-    /// Physical removal — Delete Immediately / Empty Trash (03-board-ui.md): deletes the
-    /// folder tree from disk. Irreversible, and distinct from the ordinary delete, which is a
-    /// *move* into `.trash/` — this call does **not** require the item to be in the trash first,
-    /// since Delete Immediately "skips the trash from anywhere" by design.
+    /// Physical removal — the create-undo's own primitive (13-native-undo.md: "create → remove the
+    /// created folder"): deletes the folder tree from disk. Irreversible, and distinct from the
+    /// ordinary delete, which is a *move* into `.trash/` — this call does **not** require the item to
+    /// be in the trash first, since an undone create's folder was never trashed to begin with.
     ///
     /// **A folder that is already gone is success, not an error** — checked first, before the
     /// shape guard below. A Finder deletion converges on exactly the end state a purge would