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/routes/tracking-configs/+page.svelte

@@ -181,9 +181,12 @@
 						{:else if field.type === 'grid-select' && field.gridItems}
 							<IconGridSelect items={gridItemSources[field.gridItems]()} bind:value={form[field.key]} columns={field.gridColumns ?? 2} compact />
 						{:else}
-							<input type={field.key.includes('date') ? 'date' : field.key.includes('times') ? 'text' : 'number'}
+							<input type={field.key.includes('date') ? 'date'
+									: field.key.startsWith('quiet_hours_') ? 'time'
+									: field.key.includes('times') ? 'text'
+									: 'number'}
 								bind:value={form[field.key]} min={field.min} max={field.max}
-								placeholder={field.key.includes('times') ? String(field.defaultValue ?? '') : ''}
+								placeholder={field.key.includes('times') || field.key.startsWith('quiet_hours_') ? String(field.defaultValue ?? '') : ''}
 								class="w-full px-2 py-1 border border-[var(--color-border)] rounded-md text-sm bg-[var(--color-background)]" />
 						{/if}
 					</div>