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/routes/admin/+layout.svelte

@@ -1,15 +1,16 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import type { Snippet } from 'svelte';
 	import type { LayoutData } from './$types.js';
 	import { page } from '$app/stores';
 
 	let { data, children }: { data: LayoutData; children: Snippet } = $props();
 
-	const navItems = [
-		{ href: '/admin/users', label: 'Users' },
-		{ href: '/admin/groups', label: 'Groups' },
-		{ href: '/admin/settings', label: 'Settings' }
-	] as const;
+	const navItems = $derived([
+		{ href: '/admin/users', labelKey: 'admin.users' },
+		{ href: '/admin/groups', labelKey: 'admin.groups' },
+		{ href: '/admin/settings', labelKey: 'admin.settings' }
+	]);
 
 	function isActive(href: string): boolean {
 		return $page.url.pathname === href;
@@ -20,7 +21,7 @@
 	<div class="mx-auto max-w-6xl">
 		<!-- Admin header -->
 		<div class="mb-6 flex flex-wrap items-center gap-4 rounded-xl border border-border bg-card p-4 shadow-sm">
-			<span class="text-sm font-semibold text-foreground">Admin Panel</span>
+			<span class="text-sm font-semibold text-foreground">{$t('admin.panel')}</span>
 			<div class="flex gap-1">
 				{#each navItems as item (item.href)}
 					<a
@@ -29,12 +30,12 @@
 							? 'bg-primary text-primary-foreground'
 							: 'text-muted-foreground hover:bg-accent hover:text-foreground'}"
 					>
-						{item.label}
+						{$t(item.labelKey)}
 					</a>
 				{/each}
 			</div>
 			<div class="ml-auto text-xs text-muted-foreground">
-				{data.user.displayName} (admin)
+				{data.user.displayName} ({$t('admin.role_admin').toLowerCase()})
 			</div>
 		</div>
 

src/routes/admin/groups/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import type { PageData } from './$types.js';
 	import GroupTable from '$lib/components/admin/GroupTable.svelte';
 	import { superForm } from 'sveltekit-superforms/client';
@@ -18,28 +19,28 @@
 </script>
 
 <svelte:head>
-	<title>Group Management — Admin</title>
+	<title>{$t('admin.group_management')} — {$t('admin.panel')}</title>
 </svelte:head>
 
 <div>
 	<div class="mb-6 flex items-center justify-between">
-		<h1 class="text-2xl font-bold text-card-foreground">Group Management</h1>
+		<h1 class="text-2xl font-bold text-card-foreground">{$t('admin.group_management')}</h1>
 		<button
 			type="button"
 			onclick={() => (showCreateForm = !showCreateForm)}
 			class="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:bg-primary/90 focus:outline-none focus:ring-2 focus:ring-ring"
 		>
-			{showCreateForm ? 'Cancel' : 'Create Group'}
+			{showCreateForm ? $t('common.cancel') : $t('admin.create_group')}
 		</button>
 	</div>
 
 	{#if showCreateForm}
 		<div class="mb-6 rounded-lg border border-border bg-card p-6">
-			<h2 class="mb-4 text-lg font-semibold text-card-foreground">New Group</h2>
+			<h2 class="mb-4 text-lg font-semibold text-card-foreground">{$t('admin.new_group')}</h2>
 			<form method="POST" action="?/create" use:enhance class="space-y-4">
 				<div class="grid grid-cols-1 gap-4 sm:grid-cols-2">
 					<div>
-						<label for="name" class="mb-1 block text-sm font-medium text-foreground">Name</label>
+						<label for="name" class="mb-1 block text-sm font-medium text-foreground">{$t('common.name')}</label>
 						<input
 							id="name"
 							name="name"
@@ -51,7 +52,7 @@
 						{#if $errors.name}<span class="text-xs text-destructive">{$errors.name}</span>{/if}
 					</div>
 					<div>
-						<label for="description" class="mb-1 block text-sm font-medium text-foreground">Description</label>
+						<label for="description" class="mb-1 block text-sm font-medium text-foreground">{$t('common.description')}</label>
 						<input
 							id="description"
 							name="description"
@@ -68,7 +69,7 @@
 							bind:checked={$form.isDefault}
 							class="h-4 w-4 rounded border-input"
 						/>
-						<label for="isDefault" class="text-sm font-medium text-foreground">Default group (auto-assign new users)</label>
+						<label for="isDefault" class="text-sm font-medium text-foreground">{$t('admin.default_group_hint')}</label>
 					</div>
 				</div>
 				{#if $errors._errors}
@@ -78,7 +79,7 @@
 					type="submit"
 					class="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:bg-primary/90"
 				>
-					Create Group
+					{$t('admin.create_group')}
 				</button>
 			</form>
 		</div>

src/routes/admin/settings/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import type { PageData } from './$types.js';
 	import SettingsForm from '$lib/components/admin/SettingsForm.svelte';
 
@@ -6,13 +7,13 @@
 </script>
 
 <svelte:head>
-	<title>System Settings — Admin</title>
+	<title>{$t('admin.system_settings')} — {$t('admin.panel')}</title>
 </svelte:head>
 
 <div>
 	<div class="mb-6">
-		<h1 class="text-2xl font-bold text-card-foreground">System Settings</h1>
-		<p class="mt-1 text-sm text-muted-foreground">Configure global application settings.</p>
+		<h1 class="text-2xl font-bold text-card-foreground">{$t('admin.system_settings')}</h1>
+		<p class="mt-1 text-sm text-muted-foreground">{$t('admin.settings_description')}</p>
 	</div>
 
 	<SettingsForm form={data.form} />

src/routes/admin/users/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import type { PageData } from './$types.js';
 	import UserTable from '$lib/components/admin/UserTable.svelte';
 	import { superForm } from 'sveltekit-superforms/client';
@@ -18,28 +19,28 @@
 </script>
 
 <svelte:head>
-	<title>User Management — Admin</title>
+	<title>{$t('admin.user_management')} — {$t('admin.panel')}</title>
 </svelte:head>
 
 <div>
 	<div class="mb-6 flex items-center justify-between">
-		<h1 class="text-2xl font-bold text-card-foreground">User Management</h1>
+		<h1 class="text-2xl font-bold text-card-foreground">{$t('admin.user_management')}</h1>
 		<button
 			type="button"
 			onclick={() => (showCreateForm = !showCreateForm)}
 			class="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:bg-primary/90 focus:outline-none focus:ring-2 focus:ring-ring"
 		>
-			{showCreateForm ? 'Cancel' : 'Create User'}
+			{showCreateForm ? $t('common.cancel') : $t('admin.create_user')}
 		</button>
 	</div>
 
 	{#if showCreateForm}
 		<div class="mb-6 rounded-lg border border-border bg-card p-6">
-			<h2 class="mb-4 text-lg font-semibold text-card-foreground">New User</h2>
+			<h2 class="mb-4 text-lg font-semibold text-card-foreground">{$t('admin.new_user')}</h2>
 			<form method="POST" action="?/create" use:enhance class="space-y-4">
 				<div class="grid grid-cols-1 gap-4 sm:grid-cols-2">
 					<div>
-						<label for="email" class="mb-1 block text-sm font-medium text-foreground">Email</label>
+						<label for="email" class="mb-1 block text-sm font-medium text-foreground">{$t('auth.email')}</label>
 						<input
 							id="email"
 							name="email"
@@ -51,7 +52,7 @@
 						{#if $errors.email}<span class="text-xs text-destructive">{$errors.email}</span>{/if}
 					</div>
 					<div>
-						<label for="displayName" class="mb-1 block text-sm font-medium text-foreground">Display Name</label>
+						<label for="displayName" class="mb-1 block text-sm font-medium text-foreground">{$t('auth.display_name')}</label>
 						<input
 							id="displayName"
 							name="displayName"
@@ -63,7 +64,7 @@
 						{#if $errors.displayName}<span class="text-xs text-destructive">{$errors.displayName}</span>{/if}
 					</div>
 					<div>
-						<label for="password" class="mb-1 block text-sm font-medium text-foreground">Password</label>
+						<label for="password" class="mb-1 block text-sm font-medium text-foreground">{$t('auth.password')}</label>
 						<input
 							id="password"
 							name="password"
@@ -74,15 +75,15 @@
 						{#if $errors.password}<span class="text-xs text-destructive">{$errors.password}</span>{/if}
 					</div>
 					<div>
-						<label for="role" class="mb-1 block text-sm font-medium text-foreground">Role</label>
+						<label for="role" class="mb-1 block text-sm font-medium text-foreground">{$t('admin.role_column')}</label>
 						<select
 							id="role"
 							name="role"
 							bind:value={$form.role}
 							class="w-full rounded-md border border-input bg-background px-3 py-2 text-sm text-foreground"
 						>
-							<option value="user">User</option>
-							<option value="admin">Admin</option>
+							<option value="user">{$t('admin.role_user')}</option>
+							<option value="admin">{$t('admin.role_admin')}</option>
 						</select>
 					</div>
 				</div>
@@ -93,7 +94,7 @@
 					type="submit"
 					class="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:bg-primary/90"
 				>
-					Create User
+					{$t('admin.create_user')}
 				</button>
 			</form>
 		</div>