feat: add filtering to all entity list pages

- Tracking configs: filter by name + provider type
- Template configs: filter by name + provider type
- Command configs: filter by name + provider type
- Notification trackers: filter by name + provider
- Command trackers: filter by name + provider
- Targets: filter by name (type filtering already existed)
- Nav badge counts include system-owned entities (user_id=0)
- Shows "no items match filter" vs "no items yet" empty states

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

@@ -24,7 +24,13 @@
 		return tpl?.name || `#${id}`;
 	}
 
-	let configs = $derived(commandConfigsCache.items);
+	let allCmdConfigs = $derived(commandConfigsCache.items);
+	let filterText = $state('');
+	let filterType = $state('');
+	let configs = $derived(allCmdConfigs.filter(c =>
+		(!filterText || c.name.toLowerCase().includes(filterText.toLowerCase())) &&
+		(!filterType || c.provider_type === filterType)
+	));
 	let cmdTemplateConfigs = $derived(commandTemplateConfigsCache.items);
 	const templateItems = $derived(cmdTemplateConfigs
 		.filter((c: any) => c.provider_type === form.provider_type)
@@ -229,10 +235,27 @@
 	</Card>
 {/if}
 
-{#if configs.length === 0 && !showForm}
+{#if !showForm && allCmdConfigs.length > 0}
+<div class="flex items-center gap-2 mb-3">
+	<input type="text" bind:value={filterText} placeholder={t('common.filterByName')}
+		class="flex-1 px-3 py-1.5 border border-[var(--color-border)] rounded-md text-sm bg-[var(--color-background)]" />
+	<select bind:value={filterType}
+		class="px-3 py-1.5 border border-[var(--color-border)] rounded-md text-sm bg-[var(--color-background)]">
+		<option value="">{t('common.allTypes')}</option>
+		<option value="immich">Immich</option>
+		<option value="gitea">Gitea</option>
+	</select>
+</div>
+{/if}
+
+{#if allCmdConfigs.length === 0 && !showForm}
 	<Card>
 		<EmptyState icon="mdiConsoleLine" message={t('commandConfig.noConfigs')} />
 	</Card>
+{:else if configs.length === 0 && !showForm}
+	<Card>
+		<EmptyState icon="mdiFilterOff" message={t('common.noFilterResults')} />
+	</Card>
 {:else}
 	<div class="space-y-3 stagger-children">
 		{#each configs as cfg}