chore: track all project map and index files

Add generated .pi-map.md and .pi-map.index.md files across the repository
so the project navigation maps are shared and versioned. These artifacts
are maintained by project_map_init/patch/validate and must be kept in
sync with source edits.

Note: .cache/ remains ignored (added in previous commit).

openspec/changes/workspace-first-ui/.pi-map.index.md

@@ -0,0 +1,22 @@
+# openspec/changes/workspace-first-ui (index)
+dir: openspec/changes/workspace-first-ui
+
+## role
+Design and planning documents for a workspace-first UI refresh that restructures the application around persistent writable workspaces rather than direct repository browsing.
+## parent
+index: openspec/changes/.pi-map.index.md
+map: openspec/changes/.pi-map.md
+## children
+-
+## files
+- design.md
+- proposal.md
+- spec.md
+- tasks.md
+## links
+index: openspec/changes/workspace-first-ui/.pi-map.index.md
+map: openspec/changes/workspace-first-ui/.pi-map.md
+## workflows
+-
+## dirty
+-