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/components/board/Board.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import Section from '$lib/components/section/Section.svelte';
 
 	interface SectionData {
@@ -25,21 +26,32 @@
 		}>;
 	}
 
-	interface Props {
-		sections: SectionData[];
+	interface AppData {
+		id: string;
+		name: string;
+		url: string;
+		icon: string | null;
+		iconType: string;
+		description: string | null;
+		statuses: Array<{ status: string; responseTime: number | null }>;
 	}
 
-	let { sections }: Props = $props();
+	interface Props {
+		sections: SectionData[];
+		allApps?: AppData[];
+	}
+
+	let { sections, allApps = [] }: Props = $props();
 </script>
 
 <div class="space-y-6">
 	{#if sections.length === 0}
 		<div class="rounded-xl border border-border bg-card/50 p-12 text-center">
-			<p class="text-muted-foreground">This board has no sections yet.</p>
+			<p class="text-muted-foreground">{$t('board.no_sections')}</p>
 		</div>
 	{:else}
 		{#each sections as section (section.id)}
-			<Section {section} />
+			<Section {section} {allApps} />
 		{/each}
 	{/if}
 </div>

src/lib/components/board/BoardCard.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import DynamicIcon from '$lib/components/ui/DynamicIcon.svelte';
 
 	interface BoardSummary {
@@ -39,12 +40,12 @@
 				</h3>
 				{#if board.isDefault}
 					<span class="shrink-0 rounded bg-primary/15 px-1.5 py-0.5 text-xs text-primary">
-						Default
+						{$t('board.default')}
 					</span>
 				{/if}
 				{#if board.isGuestAccessible}
 					<span class="shrink-0 rounded bg-accent px-1.5 py-0.5 text-xs text-accent-foreground">
-						Guest
+						{$t('board.guest')}
 					</span>
 				{/if}
 			</div>
@@ -52,7 +53,7 @@
 				<p class="mt-1 line-clamp-2 text-sm text-muted-foreground">{board.description}</p>
 			{/if}
 			<p class="mt-2 text-xs text-muted-foreground/70">
-				{sectionCount} section{sectionCount === 1 ? '' : 's'}
+				{$t('board.sections_count', { values: { count: sectionCount } })}
 			</p>
 		</div>
 	</div>

src/lib/components/board/BoardHeader.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import DynamicIcon from '$lib/components/ui/DynamicIcon.svelte';
 
 	interface Props {
@@ -30,14 +31,14 @@
 			href="/boards"
 			class="rounded-lg border border-border px-3 py-2 text-sm text-foreground transition-colors hover:bg-accent"
 		>
-			All Boards
+			{$t('board.all_boards')}
 		</a>
 		{#if canEdit}
 			<a
 				href="/boards/{boardId}/edit"
 				class="rounded-lg bg-primary px-3 py-2 text-sm font-medium text-primary-foreground transition-colors hover:bg-primary/90"
 			>
-				Edit
+				{$t('board.edit')}
 			</a>
 		{/if}
 	</div>

src/lib/components/board/DraggableBoard.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import { dndzone } from 'svelte-dnd-action';
 	import DraggableSection from '$lib/components/section/DraggableSection.svelte';
 
@@ -36,7 +37,7 @@
 		addWidgetSectionId: string | null;
 		onToggleAddWidget: (sectionId: string) => void;
 		onDeleteSection: (sectionId: string) => void;
-		onAddWidget: (sectionId: string, appId: string) => void;
+		onAddWidget: (sectionId: string, widgetData: string) => void;
 		onDeleteWidget: (widgetId: string) => void;
 	}
 
@@ -99,7 +100,7 @@
 
 {#if sections.length === 0}
 	<div class="rounded-xl border border-border bg-card/50 p-8 text-center">
-		<p class="text-muted-foreground">No sections yet. Add one to get started.</p>
+		<p class="text-muted-foreground">{$t('board.no_sections')}</p>
 	</div>
 {:else}
 	<div