fun: HTTP RPC framework with DI, guards, streams and codegen

- Service binding via reflection with 4 method signatures
- Dependency injection (Wired/auto tags) and guards
- Streamable HTTP (NDJSON) streaming responses
- Go/TypeScript client code generation (self-contained, with interceptors)
- Enum support, structured Result, logging
- 16 regression tests covering all fixed bugs

utils.go

@@ -0,0 +1,60 @@
+package fun
+
+import (
+	"net"
+	"net/http"
+	"strings"
+)
+
+// getIP 获取客户端真实 IP
+// 优先级：X-Forwarded-For > X-Real-IP > RemoteAddr
+func getIP(r *http.Request) string {
+	// 1. 优先获取真实 IP（多层代理时取最后一个非空段）
+	if ip := lastNonEmpty(r.Header.Get("X-Forwarded-For")); ip != "" {
+		return toLoopback(ip)
+	}
+
+	// 2. X-Real-IP（通常由 Nginx 设置）
+	if ip := strings.TrimSpace(r.Header.Get("X-Real-IP")); ip != "" {
+		return toLoopback(ip)
+	}
+
+	// 3. 最终回退到 RemoteAddr（兼容带端口、IPv6 方括号、无端口）
+	if ip := hostOf(r.RemoteAddr); ip != "" {
+		return toLoopback(ip)
+	}
+
+	return "127.0.0.1"
+}
+
+// lastNonEmpty 取 X-Forwarded-For 中最后一个非空段
+// X-Forwarded-For: client, proxy1, proxy2
+func lastNonEmpty(xff string) string {
+	parts := strings.Split(xff, ",")
+	for i := len(parts) - 1; i >= 0; i-- {
+		if ip := strings.TrimSpace(parts[i]); ip != "" {
+			return ip
+		}
+	}
+	return ""
+}
+
+// hostOf 从 RemoteAddr 中提取 IP 部分
+// "203.0.113.9:4567" → "203.0.113.9"，"[::1]:4567" → "::1"，
+// "198.51.100.88"（无端口）→ 原样返回
+func hostOf(remoteAddr string) string {
+	raw := strings.TrimSpace(remoteAddr)
+	host, _, err := net.SplitHostPort(raw)
+	if err == nil && host != "" {
+		return host
+	}
+	return raw
+}
+
+// toLoopback 回环地址统一返回 127.0.0.1，其余原样返回
+func toLoopback(ip string) string {
+	if parsed := net.ParseIP(ip); parsed != nil && parsed.IsLoopback() {
+		return "127.0.0.1"
+	}
+	return ip
+}