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/api/ai/auto-labels/route.ts

@@ -0,0 +1,121 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { auth } from '@/auth'
+import { autoLabelCreationService } from '@/lib/ai/services'
+
+/**
+ * POST /api/ai/auto-labels - Suggest new labels for a notebook
+ */
+export async function POST(request: NextRequest) {
+  try {
+    const session = await auth()
+
+    if (!session?.user?.id) {
+      return NextResponse.json(
+        { success: false, error: 'Unauthorized' },
+        { status: 401 }
+      )
+    }
+
+    const body = await request.json()
+    const { notebookId } = body
+
+    if (!notebookId || typeof notebookId !== 'string') {
+      return NextResponse.json(
+        { success: false, error: 'Missing required field: notebookId' },
+        { status: 400 }
+      )
+    }
+
+    // Check if notebook belongs to user
+    const { prisma } = await import('@/lib/prisma')
+    const notebook = await prisma.notebook.findFirst({
+      where: {
+        id: notebookId,
+        userId: session.user.id,
+      },
+    })
+
+    if (!notebook) {
+      return NextResponse.json(
+        { success: false, error: 'Notebook not found' },
+        { status: 404 }
+      )
+    }
+
+    // Get label suggestions
+    const suggestions = await autoLabelCreationService.suggestLabels(
+      notebookId,
+      session.user.id
+    )
+
+    if (!suggestions) {
+      return NextResponse.json({
+        success: true,
+        data: null,
+        message: 'No suggestions available (notebook may have fewer than 15 notes)',
+      })
+    }
+
+    return NextResponse.json({
+      success: true,
+      data: suggestions,
+    })
+  } catch (error) {
+    return NextResponse.json(
+      {
+        success: false,
+        error: error instanceof Error ? error.message : 'Failed to get label suggestions',
+      },
+      { status: 500 }
+    )
+  }
+}
+
+/**
+ * PUT /api/ai/auto-labels - Create suggested labels
+ */
+export async function PUT(request: NextRequest) {
+  try {
+    const session = await auth()
+
+    if (!session?.user?.id) {
+      return NextResponse.json(
+        { success: false, error: 'Unauthorized' },
+        { status: 401 }
+      )
+    }
+
+    const body = await request.json()
+    const { suggestions, selectedLabels } = body
+
+    if (!suggestions || !Array.isArray(selectedLabels)) {
+      return NextResponse.json(
+        { success: false, error: 'Missing required fields: suggestions, selectedLabels' },
+        { status: 400 }
+      )
+    }
+
+    // Create labels
+    const createdCount = await autoLabelCreationService.createLabels(
+      suggestions.notebookId,
+      session.user.id,
+      suggestions,
+      selectedLabels
+    )
+
+    return NextResponse.json({
+      success: true,
+      data: {
+        createdCount,
+      },
+    })
+  } catch (error) {
+    return NextResponse.json(
+      {
+        success: false,
+        error: error instanceof Error ? error.message : 'Failed to create labels',
+      },
+      { status: 500 }
+    )
+  }
+}