Show parent > child location on detail pages, add location move

- Device/component detail pages show "Parent › Child" for locations
- Device list cards show full location path
- Location edit form now includes a Parent selector to move locations
  between parents or make them top-level
- Prevents setting a location as its own parent

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/routes/(app)/devices/+page.svelte

@@ -117,8 +117,8 @@
 								<span class="text-xs text-gray-400 dark:text-gray-500">{device.year}</span>
 							{/if}
 						</div>
-						{#if device.locationName}
-							<p class="mt-1 text-xs text-gray-400 dark:text-gray-500">{device.locationName}</p>
+						{#if device.fullLocation}
+							<p class="mt-1 text-xs text-gray-400 dark:text-gray-500">{device.fullLocation}</p>
 						{/if}
 					</div>
 				</a>