Initial commit: frpc-client-win v1.0

Single-file Windows frpc service wrapper.

Features:
- Embeds frpc v0.70.1 (16.7MB) into one 18.9MB EXE
- Registers as Windows Service (auto-start, no login required)
- Auto-detects frpc config by three-tier search:
  1. frpc.ini  2. frpc.toml  3. any *.ini/*.toml in exe dir
- Self-healing supervisor: frpc crashes are restarted with
  exponential backoff (2s..60s), capped to avoid log spam
- Console subsystem so install/start show feedback
- FreeConsole on SCM start to suppress console window
- Logs to <exe-dir>/logs/service.log

Subcommands:
  install  start  stop  remove  import  -d

Smoke test (smoke_linux.go) covers all config detection paths
including the custom-name (e.g. frpc-mike.ini) use case.

internal/logger/logger.go

@@ -0,0 +1,81 @@
+// Package logger 提供一个轻量日志器,把消息写入指定目录下的 service.log。
+//
+// 设计要点:
+//
+//   - 文件日志始终启用,便于事后取证
+//   - 所有写入加锁,frpc 输出 + 本服务输出可能并发
+//   - 服务模式下,日志必须写到 EXE 同目录(SCM 默认工作目录是 System32)
+//   - 不再同时写 stdout - 服务模式已经 FreeConsole,CLI 模式 stdout 由 main 自己处理
+package logger
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+// Log 是简易同步日志器。
+type Log struct {
+	mu sync.Mutex
+	f  *os.File
+}
+
+const timeLayout = "2006-01-02 15:04:05"
+
+// New 在 logDir 下创建日志文件并返回 Log。
+//
+// logDir 必须传绝对路径;不存在会自动创建。
+func New(logDir string) (*Log, error) {
+	if err := os.MkdirAll(logDir, 0o755); err != nil {
+		return nil, err
+	}
+	f, err := os.OpenFile(
+		filepath.Join(logDir, "service.log"),
+		os.O_CREATE|os.O_APPEND|os.O_WRONLY,
+		0o644,
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &Log{f: f}, nil
+}
+
+// Close 关闭底层文件句柄。
+func (l *Log) Close() error {
+	if l == nil || l.f == nil {
+		return nil
+	}
+	return l.f.Close()
+}
+
+// Info 写一条普通日志。
+func (l *Log) Info(format string, args ...any)  { l.write("INFO", format, args...) }
+func (l *Log) Warn(format string, args ...any)  { l.write("WARN", format, args...) }
+func (l *Log) Error(format string, args ...any) { l.write("ERROR", format, args...) }
+
+// FrpcRedirect 返回一个 io.Writer,frpc 的 stdout/stderr 重定向到这里。
+func (l *Log) FrpcRedirect() io.Writer {
+	return &frpcWriter{l: l}
+}
+
+type frpcWriter struct{ l *Log }
+
+func (w *frpcWriter) Write(p []byte) (int, error) {
+	w.l.write("FRPC", "%s", string(p))
+	return len(p), nil
+}
+
+func (l *Log) write(level, format string, args ...any) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	msg := fmt.Sprintf(format, args...)
+	line := fmt.Sprintf("[%s] [%s] %s\n", time.Now().Format(timeLayout), level, msg)
+
+	if l.f != nil {
+		_, _ = l.f.WriteString(line)
+	}
+}