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/components/.pi-map.index.md

@@ -2,7 +2,7 @@
 dir: frontend/src/components
 
 ## role
-React UI component library providing reusable display elements, dashboard widgets, and page-level views for backup management, observability, media sessions, and widget configuration.
+Reusable UI component library providing presentation-layer building blocks (tables, cards, charts, dialogs, widgets) for the frontend application.
 ## parent
 index: frontend/src/.pi-map.index.md
 map: frontend/src/.pi-map.md
@@ -18,14 +18,14 @@ map: frontend/src/.pi-map.md
 - BackupDashboardWidget.tsx
 - BackupJobsTable.tsx
 - BackupRunsTable.tsx
-- BackupsPage.tsx
 - ConfirmDialog.tsx
 - DialogFooter.tsx
 - HoverEditButton.tsx
 - LibraryOverview.tsx
+- LineSeriesChart.tsx
 - MetricCard.tsx
 - NowPlaying.tsx
-- ObservabilityPage.tsx
+- PinnedServiceLink.tsx
 - SectionCard.tsx
 - SelectionRailCard.tsx
 - SessionActivityPanel.tsx