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/services/index.ts

@@ -0,0 +1,70 @@
+/**
+ * AI Services Index
+ * Central exports for all AI-powered services
+ */
+
+// Language Detection
+export { LanguageDetectionService } from './language-detection.service'
+
+// Title Suggestions
+export {
+  TitleSuggestionService,
+  titleSuggestionService,
+  type TitleSuggestion
+} from './title-suggestion.service'
+
+// Embeddings
+export {
+  EmbeddingService,
+  embeddingService,
+  type EmbeddingResult
+} from './embedding.service'
+
+// Semantic Search
+export {
+  SemanticSearchService,
+  semanticSearchService,
+  type SearchResult,
+  type SearchOptions
+} from './semantic-search.service'
+
+// Paragraph Refactor
+export {
+  ParagraphRefactorService,
+  paragraphRefactorService,
+  type RefactorMode,
+  type RefactorOption,
+  type RefactorResult,
+  REFACTOR_OPTIONS
+} from './paragraph-refactor.service'
+
+// Memory Echo
+export {
+  MemoryEchoService,
+  memoryEchoService,
+  type MemoryEchoInsight
+} from './memory-echo.service'
+
+// Batch Organization
+export {
+  BatchOrganizationService,
+  batchOrganizationService,
+  type NoteForOrganization,
+  type NotebookOrganization,
+  type OrganizationPlan
+} from './batch-organization.service'
+
+// Auto Label Creation
+export {
+  AutoLabelCreationService,
+  autoLabelCreationService,
+  type SuggestedLabel,
+  type AutoLabelSuggestion
+} from './auto-label-creation.service'
+
+// Notebook Summary
+export {
+  NotebookSummaryService,
+  notebookSummaryService,
+  type NotebookSummary
+} from './notebook-summary.service'