feat: locale-aware notification templates + UX improvements

- Add locale support to notification templates (matching command template
  pattern): TemplateSlot now has locale field with (config_id, slot_name,
  locale) uniqueness, nested API format {slot: {locale: template}}
- Migration merges separate EN/RU system configs into unified per-provider
  configs; seeds create one config per provider with multi-locale slots
- Locale-aware dispatch with EN fallback in NotificationDispatcher
- Frontend locale tabs (EN/RU) on template config editor
- Fix tracking config cards not showing default provider icons
- Global provider filter, search palette, and various UX polish

frontend/src/routes/actions/+page.svelte

@@ -13,8 +13,11 @@
 	import ConfirmModal from '$lib/components/ConfirmModal.svelte';
 	import IconButton from '$lib/components/IconButton.svelte';
 	import EntitySelect from '$lib/components/EntitySelect.svelte';
+	import CrossLink from '$lib/components/CrossLink.svelte';
 	import { snackSuccess, snackError } from '$lib/stores/snackbar.svelte';
 	import { highlightFromUrl } from '$lib/highlight';
+	import { globalProviderFilter } from '$lib/stores/provider-filter.svelte';
+	import { providerDefaultIcon } from '$lib/grid-items';
 	import RuleEditor from './RuleEditor.svelte';
 	import ExecutionHistory from './ExecutionHistory.svelte';
 	import type { Action, ActionRule } from '$lib/types';
@@ -23,7 +26,8 @@
 	let providers = $derived(providersCache.items);
 	let filterText = $state('');
 	let actions = $derived(allActions.filter((a: Action) =>
-		!filterText || a.name.toLowerCase().includes(filterText.toLowerCase()) || a.action_type.toLowerCase().includes(filterText.toLowerCase())
+		(!filterText || a.name.toLowerCase().includes(filterText.toLowerCase()) || a.action_type.toLowerCase().includes(filterText.toLowerCase())) &&
+		(!globalProviderFilter.id || a.provider_id === globalProviderFilter.id)
 	));
 
 	let showForm = $state(false);
@@ -49,7 +53,7 @@
 	}));
 
 	let providerItems = $derived(actionProviders.map((p: any) => ({
-		value: p.id, label: p.name, icon: p.icon || 'mdiServer', desc: p.type,
+		value: p.id, label: p.name, icon: providerDefaultIcon(p), desc: p.type,
 	})));
 
 	// Action types for selected provider
@@ -136,8 +140,12 @@
 		executing = { ...executing, [id]: false };
 	}
 
+	function getProvider(providerId: number) {
+		return providers.find((p: any) => p.id === providerId);
+	}
+
 	function getProviderName(providerId: number): string {
-		return providers.find((p: any) => p.id === providerId)?.name || '?';
+		return getProvider(providerId)?.name || '?';
 	}
 
 	function formatSchedule(action: Action): string {
@@ -297,7 +305,7 @@
 								<span class="text-xs px-1.5 py-0.5 rounded bg-[var(--color-muted)] text-[var(--color-muted-foreground)]">{action.action_type}</span>
 							</div>
 							<div class="flex items-center gap-3 text-xs text-[var(--color-muted-foreground)]">
-								<span>{getProviderName(action.provider_id)}</span>
+								<CrossLink href="/providers" icon={providerDefaultIcon(getProvider(action.provider_id) || {})} label={getProviderName(action.provider_id)} entityId={action.provider_id} />
 								<span>{formatSchedule(action)}</span>
 								<span>{action.rules?.length || 0} {t('actions.rules')}</span>
 								{#if action.last_run_status}