Batch of eleven Minor design-review fixes across the corpus

- 02: welcome counts are live items only; failed first opens still record;
  duplicate-identity registry records merge silently (newest wins);
  BoardStore's FolderWatcher pointer reads "below"
- 11: lane-header new-card button inventoried (click names its target lane,
  overriding 04's ⌘N rule — cross-referenced there); attachments quiet-add
  affordance listed as a twin; Undo/Redo and Pull/Push rows gain the
  abnormal-state pause, read-only lock, and unresolvable-remote conditions;
  welcome scope added to Reveal in Finder
- 03/11: one lane context menu (header or empty space) with the full
  inventory, replacing the split rows
- 09: instantiated boards are never in git mode — actual mode follows
  detection at the destination (repo-nested possible)
- 08: the app never writes an existing CLAUDE.user.md; one-time rescue
  creation stated as the exception
- README: pathfinder path corrected to ../../Kanban

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

DESIGN/08-agent-integration.md

@@ -26,7 +26,7 @@ Mechanics: version marker in the first line (`lanework-agent-guide vN`); rewritt
 
 **Ownership**: the board-root `CLAUDE.md` is **app-owned and not available for user editing** — its header says so, and user edits do not survive upgrades. This holds on every board, including repo-nested ones: the guide is auto-written there too (the untracked file in the user's repository is accepted — a board is agent-facing wherever it lives). A board-root `CLAUDE.md` found *without* the marker is displaced user content, not clobbered: its content is moved to `CLAUDE.user.md` if that name is free (otherwise the guide write is skipped with a log — user content is never destroyed), and the guide is then written.
 
-**`CLAUDE.user.md`** is the user's extension point: an optional, user-authored file at board root carrying board-specific agent instructions. The generated guide tells agents to read it when present, so it lands in agent context without the app ever touching it — the app never writes, upgrades, or validates it.
+**`CLAUDE.user.md`** is the user's extension point: an optional, user-authored file at board root carrying board-specific agent instructions. The generated guide tells agents to read it when present, so it lands in agent context without the app ever touching it — the app never writes, upgrades, or validates an *existing* `CLAUDE.user.md`; the one exception is its creation, once, to rescue displaced content (the markerless-`CLAUDE.md` relocation above, which only runs when the name is free).
 
 On git boards, a guide write rides the normal watcher → auto-commit path with an honest message ("Update agent guide (v3)"), not "External edit" (06-history-undo.md ▸ Commit messages — the non-snapshot-files rule: the committer stages the whole root, and the composer reads the subject's version from the guide's marker line, a pure function of file content).