feat(tracking): per-config quiet hours with app-level IANA timezone

Add quiet_hours_enabled/start/end to TrackingConfig (HH:MM strings
interpreted in the app-level timezone AppSetting). The dispatch path
loads the app timezone once per run and passes it through
event_allowed_by_config -> in_quiet_hours, so overnight windows like
22:00-07:00 work correctly in any IANA tz.

Frontend exposes a Timezone field under Settings and a Quiet Hours
section on the Immich tracking-config form with time-picker inputs.

frontend/src/lib/providers/immich.ts

@@ -88,6 +88,14 @@ export const immichDescriptor: ProviderDescriptor = {
 				{ key: 'memory_source', label: 'trackingConfig.memorySource', type: 'grid-select', gridItems: 'memorySourceItems', gridColumns: 2, defaultValue: 'albums' },
 			],
 		},
+		{
+			key: 'quietHours', legend: 'trackingConfig.quietHours', legendHint: 'hints.quietHours',
+			enabledField: 'quiet_hours_enabled', enabledDefault: false,
+			fields: [
+				{ key: 'quiet_hours_start', label: 'trackingConfig.quietHoursStart', type: 'number', defaultValue: '22:00' },
+				{ key: 'quiet_hours_end', label: 'trackingConfig.quietHoursEnd', type: 'number', defaultValue: '07:00' },
+			],
+		},
 	],
 
 	collectionMeta: {