feat(editor): translate FileExplorer + FileTabs to 9 locales (Editor block 2)

FileExplorer (sidebar)
- Workspace header label and the new-workspace / save-project icon
  buttons now read from t('editor.fileExplorer.*').
- Per-board section: collapse / expand toggle, status dot tooltip
  (Running / Compiled / Idle), per-board "new file" button, and the
  composite "<board name> — click to edit" hover title (the board
  name itself stays untranslated — it's a product noun like
  "Arduino Uno").
- File rows: hover title with optional "(unsaved)" suffix,
  unsaved-dot tooltip, and the right-click context menu's Rename /
  Delete commands.
- Empty-state placeholder when no boards are on the canvas.
- The window.confirm() shown before deleting a file now reads from
  t() too, so non-English users see the prompt in their language.

FileTabs (open-tabs strip above the editor)
- Per-tab close button title and the unsaved-changes dot tooltip.
- Inline confirm dialog when closing a modified file: prompt copy,
  "Close anyway" and "Cancel" buttons.

Hand-translated for all 9 locales. Hotkey hints (Ctrl+S, Strg+S)
localised per German convention; other locales keep "Ctrl+S" as the
universally-recognised label.

frontend/src/components/editor/FileExplorer.tsx

@@ -1,4 +1,5 @@
 import React, { useState, useRef, useEffect, useCallback } from 'react';
+import { useTranslation } from 'react-i18next';
 import { useEditorStore } from '../../store/useEditorStore';
 import { useSimulatorStore } from '../../store/useSimulatorStore';
 import type { BoardKind } from '../../types/board';
@@ -151,6 +152,7 @@ interface FileExplorerProps {
 }
 
 export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewClick }) => {
+  const { t } = useTranslation();
   const {
     fileGroups,
     activeFileId,
@@ -244,7 +246,7 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
     setContextMenu(null);
     const files = fileGroups[groupId] ?? [];
     if (files.length <= 1) return;
-    if (!window.confirm('Delete this file?')) return;
+    if (!window.confirm(t('editor.fileExplorer.confirmDelete'))) return;
     deleteFile(fileId);
   };
 
@@ -270,18 +272,18 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
   return (
     <div className="file-explorer">
       <div className="file-explorer-header">
-        <span className="file-explorer-title">WORKSPACE</span>
+        <span className="file-explorer-title">{t('editor.fileExplorer.workspace')}</span>
         <div className="file-explorer-header-actions">
           <button
             className="file-explorer-new-btn"
-            title="New workspace (clears boards, components, wires and files)"
+            title={t('editor.fileExplorer.newWorkspace')}
             onClick={onNewClick}
           >
             <IcoNewWorkspace />
           </button>
           <button
             className="file-explorer-save-btn"
-            title="Save project (Ctrl+S)"
+            title={t('editor.fileExplorer.saveProject')}
             onClick={onSaveClick}
           >
             <IcoSave />
@@ -313,7 +315,7 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
                   switchToBoard(board.id, groupId);
                   if (!isOpen) toggleCollapse(board.id);
                 }}
-                title={`${BOARD_KIND_LABELS[board.boardKind]} — click to edit`}
+                title={`${BOARD_KIND_LABELS[board.boardKind]} — ${t('editor.fileExplorer.clickToEdit')}`}
               >
                 <button
                   className="fe-collapse-btn"
@@ -321,7 +323,7 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
                     e.stopPropagation();
                     toggleCollapse(board.id);
                   }}
-                  title={isOpen ? 'Collapse' : 'Expand'}
+                  title={isOpen ? t('editor.fileExplorer.collapse') : t('editor.fileExplorer.expand')}
                 >
                   <IcoChevron open={isOpen} />
                 </button>
@@ -335,13 +337,19 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
                 <span
                   className="fe-status-dot"
                   style={{ background: statusColor }}
-                  title={board.running ? 'Running' : board.compiledProgram ? 'Compiled' : 'Idle'}
+                  title={
+                    board.running
+                      ? t('editor.fileExplorer.status.running')
+                      : board.compiledProgram
+                        ? t('editor.fileExplorer.status.compiled')
+                        : t('editor.fileExplorer.status.idle')
+                  }
                 />
 
                 {/* New file button — visible on hover */}
                 <button
                   className="fe-board-new-btn"
-                  title="New file in this board"
+                  title={t('editor.fileExplorer.newFileInBoard')}
                   onClick={(e) => {
                     e.stopPropagation();
                     startCreateFile(board.id, groupId);
@@ -366,7 +374,7 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
                           switchToBoard(board.id, groupId);
                           startRename(file.id, groupId);
                         }}
-                        title={`${file.name}${file.modified ? ' (unsaved)' : ''}`}
+                        title={`${file.name}${file.modified ? ` (${t('editor.fileExplorer.unsavedSuffix')})` : ''}`}
                       >
                         <span className="file-explorer-icon">
                           <FileIcon name={file.name} />
@@ -390,7 +398,7 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
                         )}
 
                         {file.modified && (
-                          <span className="file-explorer-dot" title="Unsaved changes" />
+                          <span className="file-explorer-dot" title={t('editor.fileExplorer.unsavedChanges')} />
                         )}
                       </div>
                     );
@@ -429,7 +437,7 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
         {/* Fallback: no boards yet */}
         {boards.length === 0 && (
           <div style={{ color: '#666', fontSize: 11, padding: '12px 12px', lineHeight: 1.5 }}>
-            Add a board to the canvas to start editing code.
+            {t('editor.fileExplorer.emptyState')}
           </div>
         )}
       </div>
@@ -441,14 +449,14 @@ export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick, onNewCl
           onClick={(e) => e.stopPropagation()}
         >
           <button onClick={() => startRename(contextMenu.fileId, contextMenu.boardGroupId)}>
-            Rename
+            {t('editor.fileExplorer.contextMenu.rename')}
           </button>
           <button
             className="ctx-delete"
             onClick={() => handleDelete(contextMenu.fileId, contextMenu.boardGroupId)}
             disabled={(fileGroups[contextMenu.boardGroupId] ?? []).length <= 1}
           >
-            Delete
+            {t('editor.fileExplorer.contextMenu.delete')}
           </button>
         </div>
       )}

frontend/src/components/editor/FileTabs.tsx

@@ -1,8 +1,10 @@
 import React, { useState } from 'react';
+import { useTranslation } from 'react-i18next';
 import { useEditorStore } from '../../store/useEditorStore';
 import './FileTabs.css';
 
 export const FileTabs: React.FC = () => {
+  const { t } = useTranslation();
   const { files, openFileIds, activeFileId, setActiveFile, closeFile } = useEditorStore();
   const [confirmCloseId, setConfirmCloseId] = useState<string | null>(null);
 
@@ -34,12 +36,14 @@ export const FileTabs: React.FC = () => {
             onClick={() => setActiveFile(file.id)}
             title={file.name}
           >
-            {file.modified && <span className="file-tab-modified" title="Unsaved changes" />}
+            {file.modified && (
+              <span className="file-tab-modified" title={t('editor.fileTabs.unsavedChanges')} />
+            )}
             <span className="file-tab-name">{file.name}</span>
             <button
               className="file-tab-close"
               onClick={(e) => handleCloseClick(e, file.id, file.modified)}
-              title="Close"
+              title={t('editor.fileTabs.close')}
             >
               ×
             </button>
@@ -50,12 +54,12 @@ export const FileTabs: React.FC = () => {
       {confirmCloseId && (
         <div className="ftabs-overlay" onClick={() => setConfirmCloseId(null)}>
           <div className="ftabs-confirm-box" onClick={(e) => e.stopPropagation()}>
-            <p>Close file with unsaved changes?</p>
+            <p>{t('editor.fileTabs.confirmClose')}</p>
             <div className="ftabs-confirm-actions">
               <button className="ftabs-btn-close" onClick={confirmClose}>
-                Close anyway
+                {t('editor.fileTabs.closeAnyway')}
               </button>
-              <button onClick={() => setConfirmCloseId(null)}>Cancel</button>
+              <button onClick={() => setConfirmCloseId(null)}>{t('editor.fileTabs.cancel')}</button>
             </div>
           </div>
         </div>

frontend/src/i18n/locales/de/common.json

@@ -108,6 +108,35 @@
         "cta": "Bibliotheksmanager",
         "dismiss": "Schließen"
       }
+    },
+    "fileExplorer": {
+      "workspace": "ARBEITSBEREICH",
+      "newWorkspace": "Neuer Arbeitsbereich (entfernt Boards, Bauteile, Drähte und Dateien)",
+      "saveProject": "Projekt speichern (Strg+S)",
+      "clickToEdit": "zum Bearbeiten klicken",
+      "collapse": "Einklappen",
+      "expand": "Aufklappen",
+      "newFileInBoard": "Neue Datei auf diesem Board",
+      "unsavedChanges": "Nicht gespeicherte Änderungen",
+      "unsavedSuffix": "nicht gespeichert",
+      "emptyState": "Füge ein Board zur Leinwand hinzu, um Code zu schreiben.",
+      "confirmDelete": "Diese Datei löschen?",
+      "status": {
+        "running": "Läuft",
+        "compiled": "Kompiliert",
+        "idle": "Inaktiv"
+      },
+      "contextMenu": {
+        "rename": "Umbenennen",
+        "delete": "Löschen"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Nicht gespeicherte Änderungen",
+      "close": "Schließen",
+      "confirmClose": "Datei mit nicht gespeicherten Änderungen schließen?",
+      "closeAnyway": "Trotzdem schließen",
+      "cancel": "Abbrechen"
     }
   }
 }

frontend/src/i18n/locales/en/common.json

@@ -108,6 +108,35 @@
         "cta": "Library Manager",
         "dismiss": "Dismiss"
       }
+    },
+    "fileExplorer": {
+      "workspace": "WORKSPACE",
+      "newWorkspace": "New workspace (clears boards, components, wires and files)",
+      "saveProject": "Save project (Ctrl+S)",
+      "clickToEdit": "click to edit",
+      "collapse": "Collapse",
+      "expand": "Expand",
+      "newFileInBoard": "New file in this board",
+      "unsavedChanges": "Unsaved changes",
+      "unsavedSuffix": "unsaved",
+      "emptyState": "Add a board to the canvas to start editing code.",
+      "confirmDelete": "Delete this file?",
+      "status": {
+        "running": "Running",
+        "compiled": "Compiled",
+        "idle": "Idle"
+      },
+      "contextMenu": {
+        "rename": "Rename",
+        "delete": "Delete"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Unsaved changes",
+      "close": "Close",
+      "confirmClose": "Close file with unsaved changes?",
+      "closeAnyway": "Close anyway",
+      "cancel": "Cancel"
     }
   }
 }

frontend/src/i18n/locales/es/common.json

@@ -108,6 +108,35 @@
         "cta": "Gestor de librerías",
         "dismiss": "Descartar"
       }
+    },
+    "fileExplorer": {
+      "workspace": "ESPACIO DE TRABAJO",
+      "newWorkspace": "Nuevo espacio de trabajo (borra placas, componentes, cables y archivos)",
+      "saveProject": "Guardar proyecto (Ctrl+S)",
+      "clickToEdit": "haz clic para editar",
+      "collapse": "Plegar",
+      "expand": "Expandir",
+      "newFileInBoard": "Nuevo archivo en esta placa",
+      "unsavedChanges": "Cambios sin guardar",
+      "unsavedSuffix": "sin guardar",
+      "emptyState": "Añade una placa al lienzo para empezar a editar código.",
+      "confirmDelete": "¿Eliminar este archivo?",
+      "status": {
+        "running": "En ejecución",
+        "compiled": "Compilado",
+        "idle": "Inactivo"
+      },
+      "contextMenu": {
+        "rename": "Renombrar",
+        "delete": "Eliminar"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Cambios sin guardar",
+      "close": "Cerrar",
+      "confirmClose": "¿Cerrar archivo con cambios sin guardar?",
+      "closeAnyway": "Cerrar igualmente",
+      "cancel": "Cancelar"
     }
   }
 }

frontend/src/i18n/locales/fr/common.json

@@ -108,6 +108,35 @@
         "cta": "Gestionnaire de bibliothèques",
         "dismiss": "Fermer"
       }
+    },
+    "fileExplorer": {
+      "workspace": "ESPACE DE TRAVAIL",
+      "newWorkspace": "Nouvel espace de travail (efface cartes, composants, fils et fichiers)",
+      "saveProject": "Enregistrer le projet (Ctrl+S)",
+      "clickToEdit": "cliquer pour modifier",
+      "collapse": "Réduire",
+      "expand": "Développer",
+      "newFileInBoard": "Nouveau fichier sur cette carte",
+      "unsavedChanges": "Modifications non enregistrées",
+      "unsavedSuffix": "non enregistré",
+      "emptyState": "Ajoutez une carte au canevas pour commencer à éditer du code.",
+      "confirmDelete": "Supprimer ce fichier ?",
+      "status": {
+        "running": "En cours",
+        "compiled": "Compilé",
+        "idle": "Inactif"
+      },
+      "contextMenu": {
+        "rename": "Renommer",
+        "delete": "Supprimer"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Modifications non enregistrées",
+      "close": "Fermer",
+      "confirmClose": "Fermer le fichier avec des modifications non enregistrées ?",
+      "closeAnyway": "Fermer quand même",
+      "cancel": "Annuler"
     }
   }
 }

frontend/src/i18n/locales/it/common.json

@@ -108,6 +108,35 @@
         "cta": "Gestore Librerie",
         "dismiss": "Ignora"
       }
+    },
+    "fileExplorer": {
+      "workspace": "WORKSPACE",
+      "newWorkspace": "Nuovo workspace (cancella schede, componenti, fili e file)",
+      "saveProject": "Salva progetto (Ctrl+S)",
+      "clickToEdit": "clic per modificare",
+      "collapse": "Comprimi",
+      "expand": "Espandi",
+      "newFileInBoard": "Nuovo file su questa scheda",
+      "unsavedChanges": "Modifiche non salvate",
+      "unsavedSuffix": "non salvato",
+      "emptyState": "Aggiungi una scheda sul canvas per iniziare a scrivere codice.",
+      "confirmDelete": "Eliminare questo file?",
+      "status": {
+        "running": "In esecuzione",
+        "compiled": "Compilato",
+        "idle": "Inattivo"
+      },
+      "contextMenu": {
+        "rename": "Rinomina",
+        "delete": "Elimina"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Modifiche non salvate",
+      "close": "Chiudi",
+      "confirmClose": "Chiudere il file con modifiche non salvate?",
+      "closeAnyway": "Chiudi comunque",
+      "cancel": "Annulla"
     }
   }
 }

frontend/src/i18n/locales/ja/common.json

@@ -108,6 +108,35 @@
         "cta": "ライブラリマネージャー",
         "dismiss": "閉じる"
       }
+    },
+    "fileExplorer": {
+      "workspace": "ワークスペース",
+      "newWorkspace": "新しいワークスペース（ボード、コンポーネント、配線、ファイルをすべて削除）",
+      "saveProject": "プロジェクトを保存 (Ctrl+S)",
+      "clickToEdit": "クリックして編集",
+      "collapse": "折りたたむ",
+      "expand": "展開",
+      "newFileInBoard": "このボードに新規ファイル",
+      "unsavedChanges": "未保存の変更",
+      "unsavedSuffix": "未保存",
+      "emptyState": "キャンバスにボードを追加してコードの編集を開始しましょう。",
+      "confirmDelete": "このファイルを削除しますか？",
+      "status": {
+        "running": "実行中",
+        "compiled": "コンパイル済み",
+        "idle": "アイドル"
+      },
+      "contextMenu": {
+        "rename": "名前を変更",
+        "delete": "削除"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "未保存の変更",
+      "close": "閉じる",
+      "confirmClose": "未保存の変更があるファイルを閉じますか？",
+      "closeAnyway": "それでも閉じる",
+      "cancel": "キャンセル"
     }
   }
 }

frontend/src/i18n/locales/pt-br/common.json

@@ -108,6 +108,35 @@
         "cta": "Gerenciador de Bibliotecas",
         "dismiss": "Dispensar"
       }
+    },
+    "fileExplorer": {
+      "workspace": "ESPAÇO DE TRABALHO",
+      "newWorkspace": "Novo espaço de trabalho (limpa placas, componentes, fios e arquivos)",
+      "saveProject": "Salvar projeto (Ctrl+S)",
+      "clickToEdit": "clique para editar",
+      "collapse": "Recolher",
+      "expand": "Expandir",
+      "newFileInBoard": "Novo arquivo nesta placa",
+      "unsavedChanges": "Alterações não salvas",
+      "unsavedSuffix": "não salvo",
+      "emptyState": "Adicione uma placa à tela para começar a editar código.",
+      "confirmDelete": "Excluir este arquivo?",
+      "status": {
+        "running": "Em execução",
+        "compiled": "Compilado",
+        "idle": "Inativo"
+      },
+      "contextMenu": {
+        "rename": "Renomear",
+        "delete": "Excluir"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Alterações não salvas",
+      "close": "Fechar",
+      "confirmClose": "Fechar arquivo com alterações não salvas?",
+      "closeAnyway": "Fechar mesmo assim",
+      "cancel": "Cancelar"
     }
   }
 }

frontend/src/i18n/locales/ru/common.json

@@ -108,6 +108,35 @@
         "cta": "Менеджер библиотек",
         "dismiss": "Закрыть"
       }
+    },
+    "fileExplorer": {
+      "workspace": "РАБОЧАЯ ОБЛАСТЬ",
+      "newWorkspace": "Новая рабочая область (удалит платы, компоненты, провода и файлы)",
+      "saveProject": "Сохранить проект (Ctrl+S)",
+      "clickToEdit": "нажмите, чтобы редактировать",
+      "collapse": "Свернуть",
+      "expand": "Развернуть",
+      "newFileInBoard": "Новый файл на этой плате",
+      "unsavedChanges": "Несохранённые изменения",
+      "unsavedSuffix": "не сохранено",
+      "emptyState": "Добавьте плату на холст, чтобы начать писать код.",
+      "confirmDelete": "Удалить этот файл?",
+      "status": {
+        "running": "Работает",
+        "compiled": "Скомпилировано",
+        "idle": "Простой"
+      },
+      "contextMenu": {
+        "rename": "Переименовать",
+        "delete": "Удалить"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "Несохранённые изменения",
+      "close": "Закрыть",
+      "confirmClose": "Закрыть файл с несохранёнными изменениями?",
+      "closeAnyway": "Всё равно закрыть",
+      "cancel": "Отмена"
     }
   }
 }

frontend/src/i18n/locales/zh-cn/common.json

@@ -108,6 +108,35 @@
         "cta": "库管理器",
         "dismiss": "关闭"
       }
+    },
+    "fileExplorer": {
+      "workspace": "工作区",
+      "newWorkspace": "新建工作区（清空开发板、元件、连线和文件）",
+      "saveProject": "保存项目 (Ctrl+S)",
+      "clickToEdit": "点击编辑",
+      "collapse": "折叠",
+      "expand": "展开",
+      "newFileInBoard": "在此开发板上新建文件",
+      "unsavedChanges": "未保存的更改",
+      "unsavedSuffix": "未保存",
+      "emptyState": "请将开发板添加到画布上以开始编写代码。",
+      "confirmDelete": "删除此文件？",
+      "status": {
+        "running": "运行中",
+        "compiled": "已编译",
+        "idle": "空闲"
+      },
+      "contextMenu": {
+        "rename": "重命名",
+        "delete": "删除"
+      }
+    },
+    "fileTabs": {
+      "unsavedChanges": "未保存的更改",
+      "close": "关闭",
+      "confirmClose": "确定关闭包含未保存更改的文件吗？",
+      "closeAnyway": "仍然关闭",
+      "cancel": "取消"
     }
   }
 }