feat: add provider type selector to tracking-configs, use IconGridSelect everywhere

- Tracking Configs: add provider type field (was missing entirely)
- All 4 config pages: provider type uses IconGridSelect during creation,
  shown as read-only text during editing (provider type is immutable)
- Pages: tracking-configs, command-configs, template-configs,
  command-template-configs

frontend/src/routes/command-configs/+page.svelte

@@ -12,6 +12,11 @@
 	import ConfirmModal from '$lib/components/ConfirmModal.svelte';
 	import IconButton from '$lib/components/IconButton.svelte';
 	import CrossLink from '$lib/components/CrossLink.svelte';
+	import IconGridSelect from '$lib/components/IconGridSelect.svelte';
+
+	const providerTypeItems = [
+		{ value: 'immich', icon: 'mdiCamera', label: 'Immich' },
+	];
 	import EntitySelect from '$lib/components/EntitySelect.svelte';
 	import { snackSuccess, snackError } from '$lib/stores/snackbar.svelte';
 	import { highlightFromUrl } from '$lib/highlight';
@@ -162,11 +167,12 @@
 			</div>
 
 			<div>
-				<label for="cfg-provider-type" class="block text-sm font-medium mb-1">{t('commandConfig.providerType')}</label>
-				<select id="cfg-provider-type" bind:value={form.provider_type}
-					class="w-full px-3 py-2 border border-[var(--color-border)] rounded-md text-sm bg-[var(--color-background)]">
-					<option value="immich">Immich</option>
-				</select>
+				<label class="block text-sm font-medium mb-1">{t('commandConfig.providerType')}</label>
+				{#if !editing}
+					<IconGridSelect items={providerTypeItems} bind:value={form.provider_type} columns={2} />
+				{:else}
+					<p class="text-sm text-[var(--color-muted-foreground)]">{form.provider_type}</p>
+				{/if}
 			</div>
 
 			<!-- Enabled commands -->