feat: icon-only toolbar, versioning fixes, history modal, PanelRight repositioning

- Toolbar: remove text labels from all icon buttons (AI, Save, Preview, Convert)
  all buttons now icon-only with title tooltip for accessibility
- Toolbar: reposition PanelRight (info panel toggle) to far right after three-dot menu
- Versioning: decouple getNoteHistory/restoreNoteVersion from global userAISettings.noteHistory
  now checks note.historyEnabled directly — unblocks manual per-note history
- Versioning: add 'Sauvegarder cette version' button in Versions tab of info panel
  calls commitNoteHistory with visual feedback (spinner → success state)
- note-document-info-panel: import commitNoteHistory, add isSavingVersion state
- notes.ts: fix double guard that silently blocked all history operations

memento-note/lib/config.ts

@@ -13,6 +13,11 @@ const ENV_FALLBACKS: Record<string, string> = {
   OLLAMA_BASE_URL: process.env.OLLAMA_BASE_URL || '',
   // OpenAI
   OPENAI_API_KEY: process.env.OPENAI_API_KEY || '',
+  // Anthropic (official Messages API)
+  ANTHROPIC_API_KEY: process.env.ANTHROPIC_API_KEY || '',
+  // Anthropic via OpenAI-compatible proxy / gateway
+  ANTHROPIC_CUSTOM_API_KEY: process.env.ANTHROPIC_CUSTOM_API_KEY || '',
+  ANTHROPIC_CUSTOM_BASE_URL: process.env.ANTHROPIC_CUSTOM_BASE_URL || '',
   // Custom OpenAI
   CUSTOM_OPENAI_API_KEY: process.env.CUSTOM_OPENAI_API_KEY || '',
   CUSTOM_OPENAI_BASE_URL: process.env.CUSTOM_OPENAI_BASE_URL || '',