Add video download failure reporting feature

- Introduced a new API endpoint `POST /api/v1/video/remove_watermark/report_failure` for reporting download failures.
- Added a new database table `video_download_failures` to store details about failed downloads, including domain, URL, error message, and reporting metadata.
- Updated the video handler to process failure reports and save them to the database.
- Enhanced documentation to include details about the new reporting feature and its usage.

internal/remove_watermark/handler/video_handler.go

@@ -3,6 +3,9 @@ package handler
 import (
 	"errors"
 	"net/http"
+	"net/url"
+	"strings"
+	"time"
 
 	"github.com/gin-gonic/gin"
 
@@ -25,6 +28,14 @@ type removeWatermarkRequest struct {
 	Content string `json:"content" binding:"required"`
 }
 
+type reportDownloadFailureRequest struct {
+	Domain       string `json:"domain"`
+	FailedURL    string `json:"failedUrl" binding:"required"`
+	ErrorMessage string `json:"errorMessage"`
+	Timestamp    int64  `json:"timestamp"`
+	UserAgent    string `json:"userAgent"`
+}
+
 func (h *VideoHandler) RemoveWatermark(c *gin.Context) {
 	var req removeWatermarkRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
@@ -84,3 +95,52 @@ func (h *VideoHandler) UnlockQuota(c *gin.Context) {
 		"unlocked": true,
 	}))
 }
+
+func (h *VideoHandler) ReportDownloadFailure(c *gin.Context) {
+	var req reportDownloadFailureRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "请求参数错误"))
+		return
+	}
+
+	failedURL := strings.TrimSpace(req.FailedURL)
+	if failedURL == "" {
+		c.JSON(http.StatusBadRequest, model.Error(http.StatusBadRequest, "failedUrl 不能为空"))
+		return
+	}
+
+	reportedAt := time.Now()
+	if req.Timestamp > 0 {
+		reportedAt = time.UnixMilli(req.Timestamp)
+	}
+
+	domain := strings.TrimSpace(req.Domain)
+	if domain == "" {
+		if parsed, err := url.Parse(failedURL); err == nil {
+			domain = parsed.Host
+		}
+	}
+
+	userAgent := strings.TrimSpace(req.UserAgent)
+	if userAgent == "" {
+		userAgent = c.Request.UserAgent()
+	}
+
+	report := service.DownloadFailureReport{
+		Domain:       domain,
+		FailedURL:    failedURL,
+		ErrorMessage: req.ErrorMessage,
+		ReportedAt:   reportedAt,
+		UserAgent:    userAgent,
+		ClientIP:     c.ClientIP(),
+	}
+
+	if err := h.videoService.ReportDownloadFailure(c.Request.Context(), report); err != nil {
+		c.JSON(http.StatusInternalServerError, model.Error(http.StatusInternalServerError, "上报失败，请稍后重试"))
+		return
+	}
+
+	c.JSON(http.StatusOK, model.Success(gin.H{
+		"reported": true,
+	}))
+}