fix: initialize tracing only in daemon mode, tee to daemon.log

- Move init_logging() into daemon-only branch — CLI path doesn't need
  tracing and WARN-level output could corrupt JSON/YAML stdout
- Add TeeWriter that duplicates tracing output to both stderr and
  ~/.wx-cli/daemon.log, ensuring direct invocation (WX_DAEMON_MODE=1
  without 'wx daemon start') also writes to the log file
- Keep run_start() stderr redirect as primary path; file writer is
  a safety net for edge-case direct launches

src/main.rs

@@ -18,38 +18,61 @@ fn main() {
 
 fn init_logging() {
     use tracing_subscriber::EnvFilter;
+    use std::sync::{Arc, Mutex, OnceLock};
+    use std::fs::File;
 
     // CLI 路径不需要 tracing — 只输出用户可见的 stdout/stderr。
-    // daemon 路径：tracing 直接写入 ~/.wx-cli/daemon.log，
-    // 不依赖父进程的 stderr 重定向（避免重复写入）。
-    let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| {
-        EnvFilter::new("info")
-    });
-
+    // daemon 路径：stderr 已通过 run_start() 重定向到 daemon.log，
+    // 但我们也直接写入日志文件以覆盖直接设置 WX_DAEMON_MODE=1 的情况。
+    static LOG_FILE: OnceLock<Arc<Mutex<Option<File>>>> = OnceLock::new();
+    let file_entry = LOG_FILE.get_or_init(|| {
         let _ = std::fs::create_dir_all(config::cli_dir());
-    let log_file = std::fs::OpenOptions::new()
+        Arc::new(Mutex::new(
+            std::fs::OpenOptions::new()
                 .create(true)
                 .append(true)
                 .open(config::log_path())
-        .ok();
+                .ok(),
+        ))
+    });
 
-    match log_file {
-        Some(file) => {
+    let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| {
+        EnvFilter::new("warn")
+    });
     tracing_subscriber::fmt()
         .with_target(false)
         .with_level(true)
         .with_env_filter(env_filter)
-                .with_writer(file)
-                .init();
+        .with_writer(move || {
+            let file_entry = Arc::clone(file_entry);
+            let guard = file_entry.lock().unwrap();
+            let b: Box<dyn std::io::Write + Send> = guard
+                .as_ref()
+                .and_then(|f| f.try_clone().ok())
+                .map(|f| Box::new(f) as Box<dyn std::io::Write + Send>)
+                .unwrap_or_else(|| Box::new(std::io::stderr()));
+            TeeWriter {
+                a: Box::new(std::io::stderr()),
+                b,
             }
-        None => {
-            // 文件打开失败时退回到 stderr，确保日志不会静默丢失
-            tracing_subscriber::fmt()
-                .with_target(false)
-                .with_level(true)
-                .with_env_filter(env_filter)
-                .with_writer(std::io::stderr)
+        })
         .init();
+}
+
+/// 同时写入两个 Write 目标
+struct TeeWriter {
+    a: Box<dyn std::io::Write + Send>,
+    b: Box<dyn std::io::Write + Send>,
+}
+
+impl std::io::Write for TeeWriter {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        let _ = self.b.write_all(buf);
+        self.a.write(buf)
     }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        let _ = self.b.flush();
+        self.a.flush()
     }
 }