fix: i18n system overhaul and sidebar UI bugs

- Fix LanguageProvider: add RTL support (ar/fa), translation caching,
  prevent blank flash during load, browser language detection
- Fix detect-user-language: extend whitelist from 5 to all 15 languages
- Remove hardcoded initialLanguage="fr" from auth layout
- Complete fr.json translation (all sections translated from English)
- Add missing admin.ai keys to all 13 non-English locales
- Translate ai.autoLabels, ai.batchOrganization, memoryEcho sections
  for all locales
- Remove duplicate top-level autoLabels/batchOrganization from en.json
- Fix notebook creation: replace window.location.reload() with
  createNotebookOptimistic + router.refresh()
- Fix notebook name truncation in sidebar with min-w-0
- Remove redundant router.refresh() after note creation in page.tsx

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

keep-notes/locales/it.json

@@ -63,7 +63,13 @@
       "tagsGenerationProvider": "Tags Generation Provider",
       "title": "AI Configuration",
       "updateFailed": "Failed to update AI settings",
-      "updateSuccess": "AI Settings updated successfully"
+      "updateSuccess": "AI Settings updated successfully",
+      "bestValue": "Miglior rapporto qualità/prezzo",
+      "bestQuality": "Miglior qualità",
+      "providerOllamaOption": "🦙 Ollama (Local & Free)",
+      "providerOpenAIOption": "🤖 OpenAI (GPT-5, GPT-4)",
+      "providerCustomOption": "🔧 Custom OpenAI-Compatible",
+      "saved": "(Salvato)"
     },
     "aiTest": {
       "description": "Test your AI providers for tag generation and semantic search embeddings",
@@ -156,9 +162,9 @@
       "analyzing": "Analisi delle tue note per suggerimenti etichette...",
       "create": "Crea",
       "createNewLabel": "Crea nuova etichetta",
-      "created": "{count} labels created successfully",
+      "created": "{count} etichette create con successo",
       "creating": "Creazione etichette...",
-      "description": "I've detected recurring themes in \"{notebookName}\" ({totalNotes} notes). Create labels for them?",
+      "description": "Ho rilevato temi ricorrenti in \"{notebookName}\" ({totalNotes} note). Creare etichette per essi?",
       "error": "Failed to fetch label suggestions",
       "new": "(nuovo)",
       "noLabelsSelected": "No labels selected",
@@ -580,14 +586,14 @@
   "memoryEcho": {
     "clickToView": "Clicca per visualizzare",
     "comparison": {
-      "clickToView": "Click to view note",
-      "helpful": "Helpful",
-      "helpfulQuestion": "Is this comparison helpful?",
-      "highSimilarityInsight": "These notes deal with the same topic with a high degree of similarity. They could be merged or consolidated.",
-      "notHelpful": "Not Helpful",
-      "similarityInfo": "These notes are connected by {similarity}% similarity",
-      "title": "💡 Note Comparison",
-      "untitled": "Untitled"
+      "title": "💡 Confronto note",
+      "similarityInfo": "Queste note sono collegate da {similarity}% di similarità",
+      "highSimilarityInsight": "Queste note trattano lo stesso argomento con un alto grado di similarità. Potrebbero essere fuse o consolidate.",
+      "untitled": "Senza titolo",
+      "clickToView": "Clicca per visualizzare la nota",
+      "helpfulQuestion": "Questo confronto è utile?",
+      "helpful": "Utile",
+      "notHelpful": "Non utile"
     },
     "connection": "connection",
     "connections": "Connections",
@@ -596,40 +602,40 @@
     "description": "Proactive connections between your notes",
     "dismiss": "Dismiss for now",
     "editorSection": {
-      "close": "Chiudi",
-      "compare": "Compare",
-      "compareAll": "Compare all",
-      "loading": "Loading...",
-      "merge": "Merge",
-      "mergeAll": "Merge all",
-      "title": "⚡ Connected Notes ({count})",
-      "view": "View"
+      "title": "⚡ Note connesse ({count})",
+      "loading": "Caricamento...",
+      "view": "Visualizza",
+      "compare": "Confronta",
+      "merge": "Unisci",
+      "compareAll": "Confronta tutto",
+      "mergeAll": "Unisci tutto",
+      "close": "Chiudi"
     },
-    "fused": "Fused",
+    "fused": "Fuso",
     "fusion": {
-      "archiveOriginals": "Archive original notes",
-      "cancel": "Cancel",
-      "confirmFusion": "Confirm fusion",
-      "createBacklinks": "Create backlink to original notes",
-      "edit": "Edit",
-      "error": "Failed to merge notes",
-      "finishEditing": "Finish editing",
-      "generateError": "Failed to generate fusion",
-      "generateFusion": "Generate the fusion",
-      "generating": "Generating...",
-      "keepAllTags": "Keep all tags",
-      "mergeNotes": "Merge {count} note(s)",
-      "modify": "Modify",
-      "noContentReturned": "No fusion content returned from API",
-      "notesToMerge": "📝 Notes to merge",
-      "optionalPrompt": "💬 Fusion prompt (optional)",
-      "optionsTitle": "Fusion options",
-      "previewTitle": "📝 Preview of merged note",
-      "promptPlaceholder": "Optional instructions for AI (e.g., 'Keep the formal style of note 1')...",
-      "success": "Notes merged successfully!",
-      "title": "🔗 Intelligent Fusion",
-      "unknownDate": "Unknown date",
-      "useLatestTitle": "Use latest note as title"
+      "title": "🔗 Fusione intelligente",
+      "mergeNotes": "Unisci {count} nota/e",
+      "notesToMerge": "📝 Note da unire",
+      "optionalPrompt": "💬 Prompt di fusione (opzionale)",
+      "promptPlaceholder": "Istruzioni opzionali per l'IA (es. 'Mantieni lo stile formale della nota 1')...",
+      "generateFusion": "Genera la fusione",
+      "generating": "Generazione...",
+      "previewTitle": "📝 Anteprima della nota unita",
+      "edit": "Modifica",
+      "modify": "Modifica",
+      "finishEditing": "Termina modifica",
+      "optionsTitle": "Opzioni di fusione",
+      "archiveOriginals": "Archivia note originali",
+      "keepAllTags": "Mantieni tutti i tag",
+      "useLatestTitle": "Usa la nota più recente come titolo",
+      "createBacklinks": "Crea collegamento alle note originali",
+      "cancel": "Annulla",
+      "confirmFusion": "Conferma fusione",
+      "success": "Note unite con successo!",
+      "error": "Impossibile unire le note",
+      "generateError": "Impossibile generare la fusione",
+      "noContentReturned": "Nessun contenuto di fusione restituito dall'API",
+      "unknownDate": "Data sconosciuta"
     },
     "helpful": "Helpful",
     "insightReady": "Your insight is ready!",