Whole-board copies keep GUIDs — carve-out from the copies-remint rule

Resolves the 01-vs-09/03 contradiction: Save as Template and File ▸
Duplicate copy the board folder as-is, GUIDs kept — the remint rule
governs item-level copies inside an existing board. Duplicate's
fork-keeps-history guarantee requires retention (copied .git history
must keep naming real paths); 03's Duplicate paragraph now says so.

Claude-Session: https://claude.ai/code/session_01HJ7PhFNmQ19bvy9RMD6GSb

DESIGN/03-board-ui.md

@@ -77,7 +77,7 @@ The welcome window carries over from the pathfinder unchanged — confirmed, it
 
 - Welcome: resizable, no title bar (background drag); recents list with board icon, name, location, counts; single click selects, double click opens; context menu Open / Reveal in Finder / Forget.
 - **Templates**: New Board (⌥⌘N — ⌘N is new *card*; 11-command-nexus.md) opens a Pages-style chooser with a mini per-lane preview per template. Inventory and definition format: 09-templates.md.
-- File menu: Open Recent (with Clear Menu; available everywhere), and Duplicate (⇧⌘S) — **board window only** (11-command-nexus.md), duplicating the frontmost open board to a Finder-style "copy" sibling; it never acts on a welcome-selected recent. The copy is preceded by the close flush (02-architecture.md ▸ Windows; the rule and its Edit-session exception are stated at 09-templates.md ▸ Save as Template), so neither the tree nor the copied history misses pending work. The duplicate **opens in its own board window** once copied — macOS Duplicate convention; the original stays open too. On a git board, the duplicate **keeps `.git` but has its remote configuration stripped** — remotes only: the repo-local `user.name`/`user.email` (06-history-undo.md's identity home) survives, so the fork keeps its commit identity. A fork of the board keeps its history (undo trail, delete-never-forgets — and it opens straight in git mode via 06-history-undo.md's adoption rule), but it must not silently push into the original's remote — sharing stays a deliberate per-board opt-in. (Push-on-commit lives app-side in the board registry and never carries to a new board path anyway.)
+- File menu: Open Recent (with Clear Menu; available everywhere), and Duplicate (⇧⌘S) — **board window only** (11-command-nexus.md), duplicating the frontmost open board to a Finder-style "copy" sibling; it never acts on a welcome-selected recent. The copy is preceded by the close flush (02-architecture.md ▸ Windows; the rule and its Edit-session exception are stated at 09-templates.md ▸ Save as Template), so neither the tree nor the copied history misses pending work. The duplicate **opens in its own board window** once copied — macOS Duplicate convention; the original stays open too. On a git board, the duplicate **keeps `.git` but has its remote configuration stripped** — remotes only: the repo-local `user.name`/`user.email` (06-history-undo.md's identity home) survives, so the fork keeps its commit identity. The copy keeps every GUID — a whole-board copy is 01-storage-format.md's explicit carve-out from the copies-remint rule (a new identity namespace, no collision possible), and keeping them is what keeps the copied history true: its commits name paths that still exist. A fork of the board keeps its history (undo trail, delete-never-forgets — and it opens straight in git mode via 06-history-undo.md's adoption rule), but it must not silently push into the original's remote — sharing stays a deliberate per-board opt-in. (Push-on-commit lives app-side in the board registry and never carries to a new board path anyway.)
 
 ## Editing surfaces summary