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/actions/semantic-search.ts

@@ -0,0 +1,63 @@
+'use server'
+
+import { semanticSearchService, SearchResult } from '@/lib/ai/services/semantic-search.service'
+
+export interface SemanticSearchResponse {
+  results: SearchResult[]
+  query: string
+  totalResults: number
+}
+
+/**
+ * Perform hybrid semantic + keyword search
+ * Supports contextual search within notebook (IA5)
+ */
+export async function semanticSearch(
+  query: string,
+  options?: {
+    limit?: number
+    threshold?: number
+    notebookId?: string // NEW: Filter by notebook for contextual search (IA5)
+  }
+): Promise<SemanticSearchResponse> {
+  try {
+    const results = await semanticSearchService.search(query, {
+      limit: options?.limit || 20,
+      threshold: options?.threshold || 0.6,
+      notebookId: options?.notebookId // NEW: Pass notebook filter
+    })
+
+    return {
+      results,
+      query,
+      totalResults: results.length
+    }
+  } catch (error) {
+    console.error('Error in semantic search action:', error)
+    throw error
+  }
+}
+
+/**
+ * Index a note for semantic search (generate embedding)
+ */
+export async function indexNote(noteId: string): Promise<void> {
+  try {
+    await semanticSearchService.indexNote(noteId)
+  } catch (error) {
+    console.error('Error indexing note:', error)
+    throw error
+  }
+}
+
+/**
+ * Batch index notes (for initial setup)
+ */
+export async function batchIndexNotes(noteIds: string[]): Promise<void> {
+  try {
+    await semanticSearchService.indexBatchNotes(noteIds)
+  } catch (error) {
+    console.error('Error batch indexing notes:', error)
+    throw error
+  }
+}