feat(phase2): localization EN/RU + additional widget types

- Add svelte-i18n with 224 translation keys (English + Russian)
- Language switcher in header (EN/RU toggle, persists to localStorage)
- Extract all hardcoded strings from 37 component/page files
- Add 4 new widget types: Bookmark, Note (markdown), Embed (iframe), Status
- WidgetRenderer dispatches by type, WidgetGrid supports full-width widgets
- Type-specific config forms in board editor
- Install marked for markdown rendering

src/lib/utils/validators.ts

@@ -123,6 +123,35 @@ export const updateSectionSchema = z.object({
 	isExpandedByDefault: z.boolean().optional()
 });
 
+// --- Widget Config Schemas ---
+
+export const appWidgetConfigSchema = z.object({
+	appId: z.string().min(1, 'App ID is required')
+});
+
+export const bookmarkWidgetConfigSchema = z.object({
+	url: z.string().url('Invalid URL'),
+	label: z.string().min(1, 'Label is required').max(200),
+	icon: z.string().max(100).optional(),
+	description: z.string().max(500).optional()
+});
+
+export const noteWidgetConfigSchema = z.object({
+	content: z.string().max(10000, 'Content too long'),
+	format: z.enum(['markdown', 'text']).default('markdown')
+});
+
+export const embedWidgetConfigSchema = z.object({
+	url: z.string().url('Invalid URL'),
+	height: z.number().int().min(100).max(2000).default(300),
+	sandbox: z.string().max(200).optional()
+});
+
+export const statusWidgetConfigSchema = z.object({
+	appIds: z.array(z.string().min(1)).min(1, 'At least one app is required'),
+	label: z.string().max(200).optional()
+});
+
 // --- Widget ---
 
 export const createWidgetSchema = z.object({