fix(ci): add xdg-utils for ARM64 AppImage and suppress dead_code warnings

- Add xdg-utils dependency for xdg-mime binary required by AppImage bundler
- Remove unused McpStatus struct from gemini_mcp.rs (duplicate of claude_mcp.rs)
- Add #![allow(dead_code)] to proxy models reserved for future type-safe API

src-tauri/src/gemini_mcp.rs

@@ -1,4 +1,3 @@
-use serde::{Deserialize, Serialize};
 use serde_json::{Map, Value};
 use std::fs;
 use std::path::{Path, PathBuf};
@@ -7,14 +6,6 @@ use crate::config::atomic_write;
 use crate::error::AppError;
 use crate::gemini_config::get_gemini_settings_path;
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
-pub struct McpStatus {
-    pub user_config_path: String,
-    pub user_config_exists: bool,
-    pub server_count: usize,
-}
-
 /// 获取 Gemini MCP 配置文件路径（~/.gemini/settings.json）
 fn user_config_path() -> PathBuf {
     get_gemini_settings_path()

src-tauri/src/proxy/providers/models/anthropic.rs

@@ -2,6 +2,8 @@
 //!
 //! 用于 Anthropic Messages API 的请求/响应格式转换
 
+#![allow(dead_code)]
+
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 

src-tauri/src/proxy/providers/models/openai.rs

@@ -2,6 +2,8 @@
 //!
 //! 用于 OpenAI Chat Completions API 的请求/响应格式转换
 
+#![allow(dead_code)]
+
 use serde::{Deserialize, Serialize};
 use serde_json::Value;