feat: EntitySelect palette-style entity picker, replace select dropdowns

New EntitySelect component: modal palette with search, keyboard nav,
current-value indicator (left border), smooth overlay. Replaces native
<select> dropdowns for entity selection.

Replaced selects:
- Notification Trackers: provider selector
- Command Trackers: provider + command config selectors
- Command Configs: response template selector
- Targets: telegram bot, email bot, matrix bot selectors

Added reactive $effect watchers for loadCollections and loadBotChats
since EntitySelect uses bind:value instead of onchange.

frontend/src/routes/notification-trackers/+page.svelte

@@ -15,6 +15,7 @@
 	import Hint from '$lib/components/Hint.svelte';
 	import IconButton from '$lib/components/IconButton.svelte';
 	import CrossLink from '$lib/components/CrossLink.svelte';
+	import EntitySelect from '$lib/components/EntitySelect.svelte';
 	import { snackSuccess, snackError } from '$lib/stores/snackbar.svelte';
 	import { highlightFromUrl } from '$lib/highlight';
 	import type { Tracker, ServiceProvider, NotificationTarget, TrackingConfig, TemplateConfig } from '$lib/types';
@@ -23,6 +24,7 @@
 	let loadError = $state('');
 	let notificationTrackers = $state<Tracker[]>([]);
 	let providers = $derived(providersCache.items);
+	const providerItems = $derived(providers.map(p => ({ value: p.id, label: p.name, icon: p.icon || 'mdiServer', desc: p.type })));
 	let targets = $derived(targetsCache.items);
 	let trackingConfigs = $derived(trackingConfigsCache.items);
 	let templateConfigs = $derived(templateConfigsCache.items);
@@ -77,6 +79,15 @@
 		try { collections = await api(`/providers/${form.provider_id}/collections`); } catch { collections = []; }
 	}
 
+	// Auto-load collections when provider changes via EntitySelect
+	let _prevProviderId = 0;
+	$effect(() => {
+		if (showForm && form.provider_id && form.provider_id !== _prevProviderId) {
+			_prevProviderId = form.provider_id;
+			loadCollections();
+		}
+	});
+
 	function openNew() { form = defaultForm(); editing = null; showForm = true; collections = []; previousCollectionIds = []; }
 	async function edit(trk: any) {
 		form = {
@@ -318,11 +329,8 @@
 				</div>
 			</div>
 			<div>
-				<label for="trk-provider" class="block text-sm font-medium mb-1">{t('notificationTracker.server')}</label>
-				<select id="trk-provider" bind:value={form.provider_id} onchange={loadCollections} required class="w-full px-3 py-2 border border-[var(--color-border)] rounded-md text-sm bg-[var(--color-background)]">
-					<option value={0} disabled>{t('notificationTracker.selectServer')}</option>
-					{#each providers as p}<option value={p.id}>{p.name}</option>{/each}
-				</select>
+				<label class="block text-sm font-medium mb-1">{t('notificationTracker.server')}</label>
+				<EntitySelect items={providerItems} bind:value={form.provider_id} placeholder={t('notificationTracker.selectServer')} />
 			</div>
 			{#if collections.length > 0}
 				<div>