add write_file tool for reliable file creation

src/tools.rs

@@ -233,6 +233,21 @@ pub fn discover_tools() -> serde_json::Value {
                 }
             }
         }),
+        serde_json::json!({
+            "type": "function",
+            "function": {
+                "name": "write_file",
+                "description": "将内容写入服务器上的文件。如果文件已存在会被覆盖，目录不存在会自动创建。",
+                "parameters": {
+                    "type": "object",
+                    "properties": {
+                        "path": {"type": "string", "description": "文件的绝对路径"},
+                        "content": {"type": "string", "description": "要写入的完整内容"}
+                    },
+                    "required": ["path", "content"]
+                }
+            }
+        }),
         serde_json::json!({
             "type": "function",
             "function": {
@@ -507,6 +522,25 @@ pub async fn execute_tool(
                 Err(_) => format!("timeout after {timeout_secs}s"),
             }
         }
+        "write_file" => {
+            let path_str = args["path"].as_str().unwrap_or("");
+            let content = args["content"].as_str().unwrap_or("");
+            if path_str.is_empty() {
+                return "Error: path is required".to_string();
+            }
+            let path = Path::new(path_str);
+            if let Some(parent) = path.parent() {
+                if !parent.exists() {
+                    if let Err(e) = std::fs::create_dir_all(parent) {
+                        return format!("Failed to create directory: {e}");
+                    }
+                }
+            }
+            match std::fs::write(path, content) {
+                Ok(_) => format!("Written {} bytes to {path_str}", content.len()),
+                Err(e) => format!("Failed to write {path_str}: {e}"),
+            }
+        }
         "call_gitea_api" => {
             let method = args["method"].as_str().unwrap_or("GET").to_uppercase();
             let path = args["path"].as_str().unwrap_or("").trim_start_matches('/');