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/web/src/components/features/.pi-map.md

@@ -0,0 +1,18 @@
+# apps/web/src/components/features
+dir: apps/web/src/components/features
+
+index: apps/web/src/components/features/.pi-map.index.md
+
+## role
+Contains reusable React components that implement specific product features and business logic for the web application.
+## files
+## arch
+Feature-based component organization with domain-specific UI building blocks, likely composed of atomic design elements (from components/ui) and consumed by page-level routes.
+## tags
+-
+## symbols
+-
+## workflows
+-
+## dirty
+-