请求明细支持查看原始请求/响应：OT_PROXY_LOG_RAW 开关控制，仅管理员记录与可见，流式全量捕获

- 配置: ProxyConfig.LogRaw (OT_PROXY_LOG_RAW, 默认 false)
- 存储: usage_logs 新增 raw_request/raw_response 文本列 (AutoMigrate)
- 网关: NewGateway 接收 logRaw 参数
- handlers: 三个协议入口按 开关+管理员 条件记录原始请求体
- passthrough: 非流式 copyAndCapture 捕获响应, 流式 streamCopy 累积全部原始 SSE 行, finishUsage 统一写入
- admin API: AdminUsage 返回 raw_request/raw_response (仅管理员)
- 前端: 用量页新增查看入口, 弹窗 tab 切换请求/响应
- gitignore: 修正 server/web/ 忽略规则（尾随空格导致未生效）

server/internal/proxy/passthrough.go

@@ -272,6 +272,9 @@ func (g *Gateway) copyAndCapture(c *gin.Context, ch *store.Channel, r io.Reader,
 		}
 	}
 	_, _ = c.Writer.Write(out)
+	if _, ok := c.Get("raw_request"); ok {
+		c.Set("raw_response", string(data)) // 上游原始响应（未转换）
+	}
 	g.finishUsage(c, ch, start, store.UsageStatusSuccess, "")
 }
 
@@ -283,10 +286,24 @@ func (g *Gateway) streamCopy(c *gin.Context, ch *store.Channel, r io.Reader, sta
 		flusher = nopFlusher{}
 	}
 
+	// 原始响应捕获：仅管理员且开关开启（raw_request 已 set）时累积上游原始行
+	_, capture := c.Get("raw_request")
+	var rawResp strings.Builder
+
+	// commitRaw 在记账前把已累积的原始响应写入 context
+	commitRaw := func() {
+		if capture {
+			c.Set("raw_response", rawResp.String())
+		}
+	}
+
 	scanner := newSSEScanner(r)
 	for {
 		line, err := scanner.Next()
 		if line != nil {
+			if capture {
+				rawResp.Write(line)
+			}
 			out := line
 			if lineConv != nil {
 				out = lineConv(line)
@@ -294,6 +311,7 @@ func (g *Gateway) streamCopy(c *gin.Context, ch *store.Channel, r io.Reader, sta
 			if out != nil {
 				if _, werr := w.Write(out); werr != nil {
 					// 客户端意外断开：按已生成部分收费（canceled）
+					commitRaw()
 					g.finishUsage(c, ch, start, store.UsageStatusCanceled, "client_disconnect")
 					return
 				}
@@ -307,6 +325,7 @@ func (g *Gateway) streamCopy(c *gin.Context, ch *store.Channel, r io.Reader, sta
 			}
 		}
 		if err != nil {
+			commitRaw()
 			if err == io.EOF {
 				g.finishUsage(c, ch, start, store.UsageStatusSuccess, "")
 			} else if c.Request.Context().Err() != nil {
@@ -578,6 +597,14 @@ func (g *Gateway) finishUsage(c *gin.Context, ch *store.Channel, start time.Time
 		chID = ch.ID
 	}
 
+	var rawReq, rawResp string
+	if v, ok := c.Get("raw_request"); ok {
+		rawReq, _ = v.(string)
+	}
+	if v, ok := c.Get("raw_response"); ok {
+		rawResp, _ = v.(string)
+	}
+
 	// 密钥今日 token 用量累计（配额检查用）
 	if g.lim != nil && kidVal > 0 {
 		g.lim.AddTokens(kidVal, in+out)
@@ -603,6 +630,8 @@ func (g *Gateway) finishUsage(c *gin.Context, ch *store.Channel, start time.Time
 		LatencyMS:           latency,
 		Status:              status,
 		ErrorCode:           errCodePtr,
+		RawRequest:          rawReq,
+		RawResponse:         rawResp,
 		CreatedAt:           time.Now().UTC(),
 	})
 }