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/state/.pi-map.index.md

@@ -0,0 +1,25 @@
+# apps/web/src/state (index)
+dir: apps/web/src/state
+
+## role
+Centralized React state management layer providing application-wide contexts for authentication, real-time events, notifications, session operations, user sessions, and toast notifications.
+## parent
+index: apps/web/src/.pi-map.index.md
+map: apps/web/src/.pi-map.md
+## children
+-
+## files
+- auth.tsx
+- events.tsx
+- notifications.tsx
+- session-operations.tsx
+- sessions.tsx
+- toast.tsx
+## links
+index: apps/web/src/state/.pi-map.index.md
+map: apps/web/src/state/.pi-map.md
+## workflows
+- change state behavior
+  read: auth.tsx, events.tsx, notifications.tsx
+## dirty
+-