feat: Complete internationalization and code cleanup

## Translation Files
- Add 11 new language files (es, de, pt, ru, zh, ja, ko, ar, hi, nl, pl)
- Add 100+ missing translation keys across all 15 languages
- New sections: notebook, pagination, ai.batchOrganization, ai.autoLabels
- Update nav section with workspace, quickAccess, myLibrary keys

## Component Updates
- Update 15+ components to use translation keys instead of hardcoded text
- Components: notebook dialogs, sidebar, header, note-input, ghost-tags, etc.
- Replace 80+ hardcoded English/French strings with t() calls
- Ensure consistent UI across all supported languages

## Code Quality
- Remove 77+ console.log statements from codebase
- Clean up API routes, components, hooks, and services
- Keep only essential error handling (no debugging logs)

## UI/UX Improvements
- Update Keep logo to yellow post-it style (from-yellow-400 to-amber-500)
- Change selection colors to #FEF3C6 (notebooks) and #EFB162 (nav items)
- Make "+" button permanently visible in notebooks section
- Fix grammar and syntax errors in multiple components

## Bug Fixes
- Fix JSON syntax errors in it.json, nl.json, pl.json, zh.json
- Fix syntax errors in notebook-suggestion-toast.tsx
- Fix syntax errors in use-auto-tagging.ts
- Fix syntax errors in paragraph-refactor.service.ts
- Fix duplicate "fusion" section in nl.json

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Ou une version plus courte si vous préférez :

feat(i18n): Add 15 languages, remove logs, update UI components

- Create 11 new translation files (es, de, pt, ru, zh, ja, ko, ar, hi, nl, pl)
- Add 100+ translation keys: notebook, pagination, AI features
- Update 15+ components to use translations (80+ strings)
- Remove 77+ console.log statements from codebase
- Fix JSON syntax errors in 4 translation files
- Fix component syntax errors (toast, hooks, services)
- Update logo to yellow post-it style
- Change selection colors (#FEF3C6, #EFB162)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

keep-notes/app/(main)/admin/page.tsx

@@ -6,10 +6,11 @@ import { redirect } from 'next/navigation'
 import Link from 'next/link'
 import { Button } from '@/components/ui/button'
 import { Settings } from 'lucide-react'
+import { AdminPageHeader, SettingsButton } from '@/components/admin-page-header'
 
 export default async function AdminPage() {
   const session = await auth()
-  
+
   if ((session?.user as any)?.role !== 'ADMIN') {
     redirect('/')
   }
@@ -19,18 +20,18 @@ export default async function AdminPage() {
   return (
     <div className="container mx-auto py-10 px-4">
       <div className="flex justify-between items-center mb-8">
-        <h1 className="text-3xl font-bold">User Management</h1>
+        <AdminPageHeader />
         <div className="flex gap-2">
           <Link href="/admin/settings">
             <Button variant="outline">
               <Settings className="mr-2 h-4 w-4" />
-              Settings
+              <SettingsButton />
             </Button>
           </Link>
           <CreateUserDialog />
         </div>
       </div>
-      
+
       <div className="bg-white dark:bg-zinc-900 rounded-lg shadow overflow-hidden border border-gray-200 dark:border-gray-800">
         <UserList initialUsers={users} />
       </div>