chore: regenerate stale .pi-map.md / .pi-map.index.md project maps

Project map had drifted: claimed recharts unused (was used), ObservabilityPage.tsx
exists (refactored to service-tabs/), missed JellyfinNowPlayingWidget +
authentik/backups service types. Regenerate to reflect post-change reality:
new Qbittorrent/LineSeriesChart/Prometheus{Gauge,Mean}Widget files,
service_data.py/qbittorrent_store.py, canonical prometheus-charting +
service-storage specs, archived changes.

frontend/src/integrations/.pi-map.index.md

@@ -2,13 +2,16 @@
 dir: frontend/src/integrations
 
 ## role
-Frontend integration layer that maps backend service types and widgets to their corresponding React components, metadata, and configuration schemas.
+Central registry and integration layer that maps external services and built-in widgets to their React components, metadata, and navigation entries.
 ## parent
 index: frontend/src/.pi-map.index.md
 map: frontend/src/.pi-map.md
 ## children
--
+- frontend/src/integrations/__tests__
+  index: frontend/src/integrations/__tests__/.pi-map.index.md
+  map: frontend/src/integrations/__tests__/.pi-map.md
 ## files
+- navEntries.ts
 - registry.test.ts
 - registry.ts
 ## links
@@ -16,8 +19,10 @@ index: frontend/src/integrations/.pi-map.index.md
 map: frontend/src/integrations/.pi-map.md
 ## workflows
 - change integrations behavior
-  read: registry.ts
+  read: navEntries.ts, registry.ts
 - update integrations tests
   read: registry.test.ts
+- explore integrations subdirectories
+  index: frontend/src/integrations/__tests__/.pi-map.index.md
 ## dirty
 -