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/nl.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": "Beste prijs-kwaliteit",
+      "bestQuality": "Beste kwaliteit",
+      "providerOllamaOption": "🦙 Ollama (Local & Free)",
+      "providerOpenAIOption": "🤖 OpenAI (GPT-5, GPT-4)",
+      "providerCustomOption": "🔧 Custom OpenAI-Compatible",
+      "saved": "(Opgeslagen)"
     },
     "aiTest": {
       "description": "Test your AI providers for tag generation and semantic search embeddings",
@@ -156,9 +162,9 @@
       "analyzing": "Uw notities analyseren voor labelsuggesties...",
       "create": "Maken",
       "createNewLabel": "Nieuw label maken",
-      "created": "{count} labels created successfully",
+      "created": "{count} labels succesvol aangemaakt",
       "creating": "Labels maken...",
-      "description": "I've detected recurring themes in \"{notebookName}\" ({totalNotes} notes). Create labels for them?",
+      "description": "Ik heb terugkerende themas gedetecteerd in \"{notebookName}\" ({totalNotes} notities). Labels hiervoor maken?",
       "error": "Failed to fetch label suggestions",
       "new": "(nieuw)",
       "noLabelsSelected": "No labels selected",
@@ -580,14 +586,14 @@
   "memoryEcho": {
     "clickToView": "Klik om te bekijken",
     "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": "💡 Notitie vergelijking",
+      "similarityInfo": "Deze notities zijn verbonden door {similarity}% overeenkomst",
+      "highSimilarityInsight": "Deze notities gaan over hetzelfde onderwerp met een hoge mate van overeenkomst. Ze kunnen worden samengevoegd.",
+      "untitled": "Naamloos",
+      "clickToView": "Klik om notitie te bekijken",
+      "helpfulQuestion": "Is deze vergelijking nuttig?",
+      "helpful": "Nuttig",
+      "notHelpful": "Niet nuttig"
     },
     "connection": "connection",
     "connections": "Connections",
@@ -596,40 +602,40 @@
     "description": "Proactive connections between your notes",
     "dismiss": "Dismiss for now",
     "editorSection": {
-      "close": "Sluiten",
-      "compare": "Compare",
-      "compareAll": "Compare all",
-      "loading": "Loading...",
-      "merge": "Merge",
-      "mergeAll": "Merge all",
-      "title": "⚡ Connected Notes ({count})",
-      "view": "View"
+      "title": "⚡ Verbinde notities ({count})",
+      "loading": "Laden...",
+      "view": "Bekijken",
+      "compare": "Vergelijken",
+      "merge": "Samenvoegen",
+      "compareAll": "Alles vergelijken",
+      "mergeAll": "Alles samenvoegen",
+      "close": "Sluiten"
     },
-    "fused": "Fused",
+    "fused": "Samengevoegd",
     "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": "🔗 Intelligente fusie",
+      "mergeNotes": "Voeg {count} notitie(s) samen",
+      "notesToMerge": "📝 Te samenvoegen notities",
+      "optionalPrompt": "💬 Fusie prompt (optioneel)",
+      "promptPlaceholder": "Optionele instructies voor AI (bijv. 'Behoud de formele stijl van notitie 1')...",
+      "generateFusion": "Genereer fusie",
+      "generating": "Genereren...",
+      "previewTitle": "📝 Voorbeeld van samengevoegde notitie",
+      "edit": "Bewerken",
+      "modify": "Wijzigen",
+      "finishEditing": "Bewerken voltooid",
+      "optionsTitle": "Fusie-opties",
+      "archiveOriginals": "Archiveer originele notities",
+      "keepAllTags": "Bewaar alle tags",
+      "useLatestTitle": "Gebruik meest recente notitie als titel",
+      "createBacklinks": "Maak terugverwijzing naar originele notities",
+      "cancel": "Annuleren",
+      "confirmFusion": "Bevestig fusie",
+      "success": "Notities succesvol samengevoegd!",
+      "error": "Kan notities niet samenvoegen",
+      "generateError": "Kan fusie niet genereren",
+      "noContentReturned": "Geen fusie-inhoud ontvangen van API",
+      "unknownDate": "Onbekende datum"
     },
     "helpful": "Helpful",
     "insightReady": "Your insight is ready!",