chore: archive completed OpenSpec changes

Move the following audited-and-implemented changes into
openspec/changes/archive/2026-06-12-completed-changes-archive/:

- tool-config-mount-cleanup
- config-profile-directory-mounts

Update archive README count and project map index/files accordingly.
openspec/changes/ now contains only the archive directory.

Quality gates: pytest 313 passed/34 skipped, npm run typecheck/lint clean,
npm test -- --run 87 passed

openspec/changes/archive/2026-06-12-completed-changes-archive/README.md

@@ -8,6 +8,7 @@ These OpenSpec changes have been audited against the current source tree and con
 - config-profile-git-mounts
 - config-profile-includes-ui
 - config-profile-multi-repo-mounts
+- config-profile-directory-mounts
 - container-monitoring-notifications
 - git-mount-url-validation
 - home-path-expansion
@@ -18,13 +19,14 @@ These OpenSpec changes have been audited against the current source tree and con
 - session-list-overhaul
 - ssh-key-mounting
 - terminal-fullscreen-unified-header
+- tool-config-mount-cleanup
 - tool-session-progress-and-updates
 
 ## Audit summary
 
 | Status | Count |
 |--------|-------|
-| Fully implemented | 15 |
+| Fully implemented | 17 |
 | Partially implemented | 0 (in this archive) |
 
 Audit report: `/tmp/active-changes-implementation-audit.md` (generated before archiving).