feat: RTL/i18n, AI translate+undo, no-refresh saves, settings perf

- RTL: force dir=rtl on LabelFilter, NotesViewToggle, LabelManagementDialog
- i18n: add missing keys (notifications, privacy, edit/preview, AI translate/undo)
- Settings pages: convert to Server Components (general, appearance) + loading skeleton
- AI menu: add Translate option (10 languages) + Undo AI button in toolbar
- Fix: saveInline uses REST API instead of Server Action → eliminates all implicit refreshes in list mode
- Fix: NotesTabsView notes sync effect preserves selected note on content changes
- Fix: auto-tag suggestions now filter already-assigned labels
- Fix: color change in card view uses local state (no refresh)
- Fix: nav links use <Link> for prefetching (Settings, Admin)
- Fix: suppress duplicate label suggestions already on note
- Route: add /api/ai/translate endpoint

keep-notes/app/api/ai/tags/route.ts

@@ -45,7 +45,7 @@ export async function POST(req: NextRequest) {
     // Otherwise, use legacy auto-tagging (generates new tags)
     const config = await getSystemConfig();
     const provider = getAIProvider(config);
-    const tags = await provider.generateTags(content);
+    const tags = await provider.generateTags(content, language);
 
     return NextResponse.json({ tags });
   } catch (error: any) {

keep-notes/app/api/ai/translate/route.ts

@@ -0,0 +1,30 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { auth } from '@/auth'
+import { getTagsProvider } from '@/lib/ai/factory'
+import { getSystemConfig } from '@/lib/config'
+
+export async function POST(request: NextRequest) {
+  try {
+    const session = await auth()
+    if (!session?.user?.id) {
+      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+    }
+
+    const { text, targetLanguage } = await request.json()
+
+    if (!text || !targetLanguage) {
+      return NextResponse.json({ error: 'text and targetLanguage are required' }, { status: 400 })
+    }
+
+    const config = await getSystemConfig()
+    const provider = getTagsProvider(config)
+
+    const prompt = `Translate the following text to ${targetLanguage}. Return ONLY the translated text, no explanation, no preamble, no quotes:\n\n${text}`
+
+    const translatedText = await provider.generateText(prompt)
+
+    return NextResponse.json({ translatedText: translatedText.trim() })
+  } catch (error: any) {
+    return NextResponse.json({ error: error.message || 'Translation failed' }, { status: 500 })
+  }
+}