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).

apps/api/src/auth/.pi-map.index.md

@@ -0,0 +1,24 @@
+# apps/api/src/auth (index)
+dir: apps/api/src/auth
+
+## role
+Provides authentication and authorization infrastructure for the API, including OIDC/OAuth2 integration, session management, and FastAPI dependency injection.
+## parent
+index: apps/api/src/.pi-map.index.md
+map: apps/api/src/.pi-map.md
+## children
+-
+## files
+- __init__.py
+- cookies.py
+- dependencies.py
+- oidc.py
+- session.py
+## links
+index: apps/api/src/auth/.pi-map.index.md
+map: apps/api/src/auth/.pi-map.md
+## workflows
+- change auth behavior
+  read: __init__.py, cookies.py, dependencies.py
+## dirty
+-