Build the template chooser and Save as Template

The chooser completes its three tiers: bundled by template order, then
keyed user templates, then keyless boards by display name — and a
malformed user template still lists, by folder name with the loader's
own sentence on the row, never failing its neighbours. The store is
re-scanned on every presentation and on app activation, the Reveal
round trip made honest without watching a folder 09 deliberately
leaves unwatched; Reveal lives in the chooser's header and mints the
store on first press. Save as Template repeats Duplicate's sequence —
progress row with Cancel, flush, detached cancellable copy — through
the engine: mint the store, read the next user order before the copy
can count itself, Finder-ladder the name, copy excluding .git and
.trash/, then stamp the whole template: mapping on the landed copy
through updateIndex, with no bracket because the copy lives outside
every watched board. Folder attributes deliberately don't carry — the
one lock the command stays live under is the read-only-DMG one, and
carrying its mode bits would mint a read-only template in the user's
own store; the command gates instead on the real hazard, unsaved card
content. A signpost names the template only when the ladder renamed
it. One name ladder now serves Duplicate and the store.

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

Kanban/KanbanApp.swift

@@ -164,7 +164,7 @@ struct KanbanApp: App {
             Divider()
 
             DuplicateBoardCommand(appModel: appModel)
-            SaveAsTemplateCommand()
+            SaveAsTemplateCommand(appModel: appModel)
             RevealInFinderCommand()
             AddAttachmentCommand()