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/lib/ai/factory.ts

@@ -20,7 +20,6 @@ function createOpenAIProvider(config: Record<string, string>, modelName: string,
   const apiKey = config?.OPENAI_API_KEY || process.env.OPENAI_API_KEY || '';
 
   if (!apiKey) {
-    console.warn('OPENAI_API_KEY non configurée.');
   }
 
   return new OpenAIProvider(apiKey, modelName, embeddingModelName);
@@ -31,11 +30,9 @@ function createCustomOpenAIProvider(config: Record<string, string>, modelName: s
   const baseUrl = config?.CUSTOM_OPENAI_BASE_URL || process.env.CUSTOM_OPENAI_BASE_URL || '';
 
   if (!apiKey) {
-    console.warn('CUSTOM_OPENAI_API_KEY non configurée.');
   }
 
   if (!baseUrl) {
-    console.warn('CUSTOM_OPENAI_BASE_URL non configurée.');
   }
 
   return new CustomOpenAIProvider(apiKey, baseUrl, modelName, embeddingModelName);
@@ -50,7 +47,6 @@ function getProviderInstance(providerType: ProviderType, config: Record<string,
     case 'custom':
       return createCustomOpenAIProvider(config, modelName, embeddingModelName);
     default:
-      console.warn(`Provider AI inconnu: ${providerType}, utilisation de Ollama par défaut`);
       return createOllamaProvider(config, modelName, embeddingModelName);
   }
 }