feat: obsolete medication archiving, start date, and UI improvements (#215)

* feat: obsolete medication archiving, start date, and UI improvements

- Add soft-archive (obsolete) for medications with dedicated section and toggle
- Add medication start date field with date picker and validation
- Add obsolete/reactivate API endpoints with proper auth
- Filter obsolete meds from schedule, coverage, planner, and notifications
- Improve UserFilterModal with intake schedules, stock badges, and click-to-open
- Improve dashboard taken-by badges with per-intake bell icons
- Add Escape key support to ConfirmModal and MobileEditModal
- Fix Lightbox close button positioning near image
- Add read-only mode support for MobileEditModal
- DB migrations: 0008 (is_obsolete, obsolete_at), 0009 (medication_start_date)
- All user-facing text uses i18n keys (en + de)

* test: fix tests for obsolete medications and UI changes

- Backend: add is_obsolete, obsolete_at, medication_start_date columns to test schemas
- Backend: add test medication inserts in planner tests for active-med filtering
- Frontend: update useMedications URL to include includeObsolete param
- Frontend: fix MobileEditModal selectors and validation assertions
- Frontend: add onClearUser prop to UserFilterModal test renders
- Frontend: fix MedicationsPage and DashboardPage test assertions

frontend/src/App.tsx

@@ -454,6 +454,11 @@ function AppContent() {
 				coverage={coverage}
 				settings={stockThresholds}
 				onClose={closeUserFilter}
+				onClearUser={() => {
+					setSelectedUser(null);
+					// Replace the userFilter history entry so it doesn't remain on the stack
+					window.history.replaceState(null, "");
+				}}
 				onOpenMedDetail={openMedDetail}
 			/>