feat: UX improvements — secure webhooks, locale fixes, dynamic languages, UI polish

- Remove top paginator from dashboard events, keep only bottom
- Fix test message locale: pass UI locale to email/matrix bot tests
- Convert webhook auth mode from text input to icon grid selector
- Generate secure UUID tokens for webhook URLs instead of sequential IDs
- Move Recent Payloads into per-provider expandable container (lazy-loaded)
- Make template config languages dynamic via app settings instead of hardcoded
- Change default dev port to 5175

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

@@ -4,7 +4,7 @@
 	import { api } from '$lib/api';
 	import { t } from '$lib/i18n';
 	import { sanitizePreview } from '$lib/sanitize';
-	import { commandTemplateConfigsCache } from '$lib/stores/caches.svelte';
+	import { commandTemplateConfigsCache, supportedLocalesCache } from '$lib/stores/caches.svelte';
 	import PageHeader from '$lib/components/PageHeader.svelte';
 	import Card from '$lib/components/Card.svelte';
 	import Loading from '$lib/components/Loading.svelte';
@@ -38,7 +38,7 @@
 		description: string;
 	}
 
-	const LOCALES = ['en', 'ru'] as const;
+	let LOCALES = $derived(supportedLocalesCache.items);
 
 	let allCmdTplConfigs = $state<CmdTemplateConfig[]>([]);
 	let filterText = $state('');
@@ -132,6 +132,7 @@
 				commandTemplateConfigsCache.fetch(true),
 				api('/providers/capabilities'),
 				api('/command-template-configs/variables'),
+				supportedLocalesCache.fetch(),
 			]);
 			allCmdTplConfigs = cfgs;
 			allCapabilities = caps;