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/register/+page.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import { t } from 'svelte-i18n';
 	import { superForm } from 'sveltekit-superforms';
 	import type { PageData } from './$types.js';
 	import AmbientBackground from '$lib/components/background/AmbientBackground.svelte';
@@ -9,7 +10,7 @@
 </script>
 
 <svelte:head>
-	<title>Register — Web App Launcher</title>
+	<title>{$t('auth.register')} — {$t('app_title')}</title>
 </svelte:head>
 
 <AmbientBackground />
@@ -34,14 +35,14 @@
 					<line x1="22" y1="11" x2="16" y2="11" />
 				</svg>
 			</div>
-			<h1 class="text-2xl font-bold text-card-foreground">Create Account</h1>
-			<p class="mt-1 text-sm text-muted-foreground">Get started with App Launcher</p>
+			<h1 class="text-2xl font-bold text-card-foreground">{$t('auth.register_title')}</h1>
+			<p class="mt-1 text-sm text-muted-foreground">{$t('auth.register_subtitle')}</p>
 		</div>
 
 		<form method="POST" use:enhance class="space-y-4">
 			<div>
 				<label for="displayName" class="mb-1 block text-sm font-medium text-card-foreground">
-					Display Name
+					{$t('auth.display_name')}
 				</label>
 				<input
 					id="displayName"
@@ -50,7 +51,7 @@
 					autocomplete="name"
 					bind:value={$form.displayName}
 					class="w-full rounded-lg border border-input bg-background px-3 py-2.5 text-sm text-foreground placeholder:text-muted-foreground transition-colors focus:border-primary focus:outline-none focus:ring-2 focus:ring-ring/30"
-					placeholder="Your name"
+					placeholder={$t('auth.display_name_placeholder')}
 				/>
 				{#if $errors.displayName}
 					<p class="mt-1 text-sm text-destructive">{$errors.displayName[0]}</p>
@@ -59,7 +60,7 @@
 
 			<div>
 				<label for="email" class="mb-1 block text-sm font-medium text-card-foreground">
-					Email
+					{$t('auth.email')}
 				</label>
 				<input
 					id="email"
@@ -68,7 +69,7 @@
 					autocomplete="email"
 					bind:value={$form.email}
 					class="w-full rounded-lg border border-input bg-background px-3 py-2.5 text-sm text-foreground placeholder:text-muted-foreground transition-colors focus:border-primary focus:outline-none focus:ring-2 focus:ring-ring/30"
-					placeholder="you@example.com"
+					placeholder={$t('auth.email_placeholder')}
 				/>
 				{#if $errors.email}
 					<p class="mt-1 text-sm text-destructive">{$errors.email[0]}</p>
@@ -77,7 +78,7 @@
 
 			<div>
 				<label for="password" class="mb-1 block text-sm font-medium text-card-foreground">
-					Password
+					{$t('auth.password')}
 				</label>
 				<input
 					id="password"
@@ -86,7 +87,7 @@
 					autocomplete="new-password"
 					bind:value={$form.password}
 					class="w-full rounded-lg border border-input bg-background px-3 py-2.5 text-sm text-foreground placeholder:text-muted-foreground transition-colors focus:border-primary focus:outline-none focus:ring-2 focus:ring-ring/30"
-					placeholder="At least 6 characters"
+					placeholder={$t('auth.password_placeholder_register')}
 				/>
 				{#if $errors.password}
 					<p class="mt-1 text-sm text-destructive">{$errors.password[0]}</p>
@@ -101,17 +102,17 @@
 				{#if $submitting}
 					<span class="flex items-center justify-center gap-2">
 						<span class="h-4 w-4 animate-spin rounded-full border-2 border-primary-foreground border-t-transparent"></span>
-						Creating account...
+						{$t('auth.register_submitting')}
 					</span>
 				{:else}
-					Create Account
+					{$t('auth.register_submit')}
 				{/if}
 			</button>
 		</form>
 
 		<p class="mt-6 text-center text-sm text-muted-foreground">
-			Already have an account?
-			<a href="/login" class="font-medium text-primary hover:underline">Sign in</a>
+			{$t('auth.have_account')}
+			<a href="/login" class="font-medium text-primary hover:underline">{$t('auth.sign_in_link')}</a>
 		</p>
 	</div>
 </main>