chore: archive 15 completed OpenSpec changes

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

- backend-frontend-refactoring
- config-profile-git-mounts
- config-profile-includes-ui
- config-profile-multi-repo-mounts
- container-monitoring-notifications
- git-mount-url-validation
- home-path-expansion
- mobile-terminal-ux
- mount-specificity-ordering
- notification-center
- persistent-terminal-sessions
- session-list-overhaul
- ssh-key-mounting
- terminal-fullscreen-unified-header
- tool-session-progress-and-updates

Also regenerated .pi-map*.md files for openspec/changes so the
remaining active changes (multi-session-terminal-ux, reorganize-long-files,
working-copies, workspace-first-ui) reflect the new layout.

openspec/changes/archive/2026-05-22-git-repo-working-clones/.pi-map.index.md

@@ -1,11 +1,11 @@
-# openspec/changes/archive/2026-05-22-git-repo-working-clones (index)
-dir: openspec/changes/archive/2026-05-22-git-repo-working-clones
+# archive/2026-05-22-git-repo-working-clones (index)
+dir: archive/2026-05-22-git-repo-working-clones
 
 ## role
-Design and planning documents for migrating Git repository infrastructure from bare/mirror clones to working-tree clones with proper branch initialization.
+Contains historical design documents and task tracking for migrating the Git backend from bare/mirror repositories to working-tree clones with proper branch initialization.
 ## parent
-index: openspec/changes/archive/.pi-map.index.md
-map: openspec/changes/archive/.pi-map.md
+index: archive/.pi-map.index.md
+map: archive/.pi-map.md
 ## children
 -
 ## files
@@ -13,8 +13,8 @@ map: openspec/changes/archive/.pi-map.md
 - proposal.md
 - tasks.md
 ## links
-index: openspec/changes/archive/2026-05-22-git-repo-working-clones/.pi-map.index.md
-map: openspec/changes/archive/2026-05-22-git-repo-working-clones/.pi-map.md
+index: archive/2026-05-22-git-repo-working-clones/.pi-map.index.md
+map: archive/2026-05-22-git-repo-working-clones/.pi-map.md
 ## workflows
 -
 ## dirty

openspec/changes/archive/2026-05-22-git-repo-working-clones/.pi-map.md

@@ -1,16 +1,16 @@
-# openspec/changes/archive/2026-05-22-git-repo-working-clones
-dir: openspec/changes/archive/2026-05-22-git-repo-working-clones
+# archive/2026-05-22-git-repo-working-clones
+dir: archive/2026-05-22-git-repo-working-clones
 
-index: openspec/changes/archive/2026-05-22-git-repo-working-clones/.pi-map.index.md
+index: archive/2026-05-22-git-repo-working-clones/.pi-map.index.md
 
 ## role
-Design and planning documents for migrating Git repository infrastructure from bare/mirror clones to working-tree clones with proper branch initialization.
+Contains historical design documents and task tracking for migrating the Git backend from bare/mirror repositories to working-tree clones with proper branch initialization.
 ## files
 - design.md | Design document for migrating repository creation from bare/mirror repos to working-tree repos with proper branch initialization | dep: git, repository backend, workspace UI, file browser, commit editor, git toolbar
 - proposal.md | Proposes changes to repository creation and git operations to use normal working clones instead of mirrored bare repositories
 - tasks.md | A task tracking document for backend Git repository creation and synchronization improvements with test coverage and quality gates.
 ## arch
-Documentation-driven change management using structured design proposals (design.md, proposal.md) with task tracking (tasks.md) for incremental backend Git operations refactoring.
+Documentation-driven planning artifacts using markdown-based design proposals, technical specifications, and structured task tracking with quality gates and test coverage requirements.
 ## tags
 design, repository, creation, git, document, bare, repos, working
 ## symbols