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

README.md

@@ -30,7 +30,7 @@ Lanework is in early development. This list tracks what has actually shipped and
 
 - **The welcome screen** — branding and two actions on the left, recents on the right: board icon, name, containing folder, and the lane/card counts stamped at last close, newest first. The list never opens a board to build itself, so a huge board or an offline volume costs nothing. Single click selects, double click or Return opens, and a context menu carries Open, Reveal in Finder, and Forget. A board that failed to open or restore says so **on its own row**, in the warning tint, carrying the loader's specifics rather than a modal at launch; a board whose bookmark no longer resolves dims to Unavailable with Open and Reveal off and Forget still live; and a failure naming no known board keeps a list of its own rather than vanishing. File ▸ Open Recent lists the same boards — unavailable ones disabled — with Clear Menu at the bottom, which forgets every record because here the registry *is* the menu.
 
-- **New Board and Duplicate** — File ▸ New Board… (⌥⌘N) opens a Pages-style template chooser with a mini per-lane preview per template, then a save panel seeded with the template's own name; the new board's frontmatter title is the document name you chose, so the window title and the Finder name start out matching. **A template is itself a board** — an ordinary schema-valid folder read by the ordinary loader, so its display name, icon, blurb and lanes all come off its own `index.md`, and authoring one is adding a folder rather than writing code. Creating from one copies that folder: fresh GUIDs for every lane and card, `created`/`modified` stamped today (born, not forked from the template), the blurb becoming the new board's description, attachments and card bodies byte for byte, strays and symlinks carried verbatim — and `.git` and `.trash/` deliberately left behind, so a new board is never silently in git mode and never born with trash. Nothing half-made is ever left where you pointed: a create that fails or is cancelled removes its own partial, and a name already taken is refused rather than replaced. File ▸ Duplicate (⇧⌘S) forks the frontmost board to a Finder-style "Board copy" sibling (then "copy 2", "copy 3"), preceded by the pending-work flush so the copy misses nothing and with the original left open beside it. The copy is literal: every GUID kept — a whole-board copy is a new identity namespace — `.trash/` carried along so the copy matches its own copied history, strays and timestamps untouched.
+- **New Board and Duplicate** — File ▸ New Board… (⌥⌘N) opens a Pages-style template chooser with a mini per-lane preview per template, then a save panel seeded with the template's own name; the new board's frontmatter title is the document name you chose, so the window title and the Finder name start out matching. **A template is itself a board** — an ordinary schema-valid folder read by the ordinary loader, so its display name, icon, blurb and lanes all come off its own `index.md`, and authoring one is adding a folder rather than writing code. Creating from one copies that folder: fresh GUIDs for every lane and card, `created`/`modified` stamped today (born, not forked from the template), the blurb becoming the new board's description, attachments and card bodies byte for byte, strays and symlinks carried verbatim — and `.git` and `.trash/` deliberately left behind, so a new board is never silently in git mode and never born with trash. Nothing half-made is ever left where you pointed: a create that fails or is cancelled removes its own partial, and a name already taken is refused rather than replaced. The chooser lists **your own templates** after the bundled ten — keyed ones in the order they carry, then keyless boards by name — and a button beside its heading reveals the templates folder in the Finder, creating it if you've never used one: they're plain board folders in there, so dropping a board in makes it a template, no key required, and the app never edits what it didn't write. A folder it can't read is **still listed**, marked and carrying the loader's own sentence, because one bad template must never take the chooser down with it. **File ▸ Save as Template** copies the frontmost board into that folder — pending work flushed first so it misses no keystroke, `.git` and `.trash/` left behind (a template is content, not history, and not a fork), everything else including `CLAUDE.user.md` and every GUID and timestamp carried verbatim, and a chooser position appended after your existing templates. A name already in the folder auto-renames Finder-style ("Roadmap 2") rather than overwriting or refusing, the copy is cancellable from its progress row (cancelling removes the partial), and a quiet line tells you which template you just made. File ▸ Duplicate (⇧⌘S) forks the frontmost board to a Finder-style "Board copy" sibling (then "copy 2", "copy 3"), preceded by the pending-work flush so the copy misses nothing and with the original left open beside it. The copy is literal: every GUID kept — a whole-board copy is a new identity namespace — `.trash/` carried along so the copy matches its own copied history, strays and timestamps untouched.
 
 - **The card window** — ⌘↩ or a double-click opens a card in its own window: two full-height, independently scrolling columns — a wide body column and a narrow attributes sidebar whose fixed width is derived from font metrics, so the window's resize flex all goes to the body. The title bar carries the card's title live and subtitles it "⟨board⟩ › ⟨lane⟩", following the card as it moves between lanes and re-reading the board's name as it's renamed. The body column shows the title, a quiet created/modified/by line built from whichever frontmatter keys exist, and the body itself; the sidebar leads with the Attachments section (below) and its remaining sections are stacked headers awaiting their content. Reopening a card focuses the window it already has, and the window closes itself the moment its card stops being on the board — moved to the trash (entering the trash counts as deleted), gone with its deleted lane, purged, or moved to another board; a dirty Edit buffer flushes into the card's new location first, so the keystrokes survive a later restore.