feat: PATH 配置文件/预设切换 — 保存、加载、一键应用不同场景的 PATH 配置

- 新增 profiles.rs: list/save/load/delete/rename 五个 Rust 命令
- 配置文件存储在 %APPDATA%/.patheditor/profiles/<name>.json
- ProfileDialog: 保存当前 PATH、加载预览、一键应用到注册表
- 工具栏新增「配置」按钮

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/i18n/locales/en.json

@@ -22,6 +22,7 @@
     "cancel": "Cancel",
     "help": "Help",
     "analyze": "Analyze",
+    "profiles": "Profiles",
     "undo": "Undo",
     "redo": "Redo",
     "darkMode": "Dark Mode",
@@ -83,6 +84,19 @@
     "searchPlaceholder": "Search executable name...",
     "conflictCount": "{{count}} file conflict(s) found"
   },
+  "profile": {
+    "title": "PATH Profiles",
+    "saveCurrent": "Save Current as Profile",
+    "namePlaceholder": "Profile name...",
+    "save": "Save",
+    "load": "Load",
+    "apply": "Apply",
+    "delete": "Delete",
+    "rename": "Rename",
+    "noProfiles": "No saved profiles",
+    "applyConfirm": "This will overwrite current PATH with profile \"{{name}}\" and write to registry. Confirm?",
+    "deleted": "Profile \"{{name}}\" deleted"
+  },
   "help": {
     "content": "PathEditor v4.0 — Windows System Environment Variable (PATH) Editor\n\nFeatures:\n• Create/Edit/Delete path entries\n• Move Up/Down to adjust priority\n• One-click cleanup of invalid & duplicate paths\n• Import/Export JSON, CSV, TXT formats\n• Full Undo/Redo support\n\nShortcuts:\n• Ctrl+N New\n• Ctrl+S Save\n• Ctrl+Z Undo\n• Ctrl+Y Redo\n• Ctrl+F Search\n• Delete Delete selected\n• F1 Help\n\nAuthor: 刘航宇\nGitHub: https://github.com/LHY0125/PathEditor"
   }