feat(prompts+i18n): add prompt management and improve prompt editor i18n (#193)

* feat(prompts): add prompt management across Tauri service and React UI

- backend: add commands/prompt.rs, services/prompt.rs, register in commands/mod.rs and lib.rs, refine app_config.rs
- frontend: add PromptPanel, PromptFormModal, PromptListItem, MarkdownEditor, usePromptActions, integrate in App.tsx
- api: add src/lib/api/prompts.ts
- i18n: update src/i18n/locales/{en,zh}.json
- build: update package.json and pnpm-lock.yaml

* feat(i18n): improve i18n for prompts and Markdown editor

- update src/i18n/locales/{en,zh}.json keys and strings
- apply i18n in PromptFormModal, PromptPanel, and MarkdownEditor
- align prompt text with src-tauri/src/services/prompt.rs

* feat(prompts): add enable/disable toggle and simplify panel UI

- Add PromptToggle component and integrate in prompt list items
- Implement toggleEnabled with optimistic update; enable via API, disable via upsert with enabled=false;
  reload after success
- Simplify PromptPanel: remove file import and current-file preview to keep CRUD flow focused
- Tweak header controls style (use mcp variant) and minor copy: rename “Prompt Management” to “Prompts”
- i18n: add disableSuccess/disableFailed messages
- Backend (Tauri): prevent duplicate backups when importing original prompt content

* style: unify code formatting with trailing commas

* feat(prompts): add Gemini filename support to PromptFormModal

Update filename mapping to use Record<AppId, string> pattern, supporting
GEMINI.md alongside CLAUDE.md and AGENTS.md.

* fix(prompts): sync enabled prompt to file when updating

When updating a prompt that is currently enabled, automatically sync
the updated content to the corresponding live file (CLAUDE.md/AGENTS.md/GEMINI.md).

This ensures the active prompt file always reflects the latest content
when editing enabled prompts.

src/i18n/locales/zh.json

@@ -550,5 +550,46 @@
         "description": "Context7 文档搜索工具，提供最新的库文档和代码示例，配置 key 会有更高限额"
       }
     }
+  },
+  "prompts": {
+    "manage": "提示词",
+    "title": "{{appName}} 提示词管理",
+    "claudeTitle": "Claude 提示词管理",
+    "codexTitle": "Codex 提示词管理",
+    "add": "添加提示词",
+    "edit": "编辑提示词",
+    "addTitle": "添加 {{appName}} 提示词",
+    "editTitle": "编辑 {{appName}} 提示词",
+    "import": "导入现有",
+    "count": "共 {{count}} 个提示词",
+    "enabled": "已启用",
+    "enable": "启用",
+    "enabledName": "已启用: {{name}}",
+    "noneEnabled": "未启用任何提示词",
+    "currentFile": "当前 {{filename}} 内容",
+    "empty": "暂无提示词",
+    "emptyDescription": "点击右上角按钮添加或导入提示词",
+    "loading": "加载中...",
+    "name": "名称",
+    "namePlaceholder": "例如：项目默认提示词",
+    "description": "描述",
+    "descriptionPlaceholder": "可选的描述信息",
+    "content": "内容",
+    "contentPlaceholder": "# {{filename}}\n\n在此输入提示词内容...",
+    "loadFailed": "加载提示词失败",
+    "saveSuccess": "保存成功",
+    "saveFailed": "保存失败",
+    "deleteSuccess": "删除成功",
+    "deleteFailed": "删除失败",
+    "enableSuccess": "启用成功",
+    "enableFailed": "启用失败",
+    "disableSuccess": "禁用成功",
+    "disableFailed": "禁用失败",
+    "importSuccess": "导入成功",
+    "importFailed": "导入失败",
+    "confirm": {
+      "deleteTitle": "确认删除",
+      "deleteMessage": "确定要删除提示词 \"{{name}}\" 吗？"
+    }
   }
 }