feat(api): add internal alerts reporting endpoint with deduplication

Add ReportAlerts endpoint for Data Plane to report alerts to Control Plane
with fingerprint-based deduplication using a 5-minute cooldown period.

Changes:
- Add POST /internal/alerts/report endpoint with validation
- Add Fingerprint field to Alert model for deduplication
- Extend GetAPIKeyStatsSummary with optional time range filtering
  using since/until query parameters to query from log records

internal/api/apikey_stats_handler.go

@@ -2,6 +2,8 @@ package api
 
 import (
 	"net/http"
+	"strconv"
+	"time"
 
 	"github.com/ez-api/ez-api/internal/model"
 	"github.com/gin-gonic/gin"
@@ -21,6 +23,8 @@ type APIKeyStatsSummaryResponse struct {
 // @Tags         admin
 // @Produce      json
 // @Security     AdminAuth
+// @Param        since  query     int  false  "Start time (unix seconds)"
+// @Param        until  query     int  false  "End time (unix seconds)"
 // @Success      200  {object}  APIKeyStatsSummaryResponse
 // @Failure      500  {object}  gin.H
 // @Router       /admin/apikey-stats/summary [get]
@@ -30,6 +34,28 @@ func (h *AdminHandler) GetAPIKeyStatsSummary(c *gin.Context) {
 		return
 	}
 
+	// Parse optional time range parameters
+	var sinceTime, untilTime *time.Time
+	if sinceStr := c.Query("since"); sinceStr != "" {
+		if ts, err := strconv.ParseInt(sinceStr, 10, 64); err == nil {
+			t := time.Unix(ts, 0).UTC()
+			sinceTime = &t
+		}
+	}
+	if untilStr := c.Query("until"); untilStr != "" {
+		if ts, err := strconv.ParseInt(untilStr, 10, 64); err == nil {
+			t := time.Unix(ts, 0).UTC()
+			untilTime = &t
+		}
+	}
+
+	// If time range specified, query from LogRecord table
+	if sinceTime != nil || untilTime != nil {
+		h.getAPIKeyStatsFromLogs(c, sinceTime, untilTime)
+		return
+	}
+
+	// Default: use aggregated stats from APIKey table (all-time)
 	var totals struct {
 		TotalRequests   int64 `json:"total_requests"`
 		SuccessRequests int64 `json:"success_requests"`
@@ -65,3 +91,53 @@ func (h *AdminHandler) GetAPIKeyStatsSummary(c *gin.Context) {
 		FailureRate:     failureRate,
 	})
 }
+
+// getAPIKeyStatsFromLogs calculates stats from log records for a specific time range
+func (h *AdminHandler) getAPIKeyStatsFromLogs(c *gin.Context, sinceTime, untilTime *time.Time) {
+	q := h.logBaseQuery()
+
+	if sinceTime != nil {
+		q = q.Where("created_at >= ?", *sinceTime)
+	}
+	if untilTime != nil {
+		q = q.Where("created_at <= ?", *untilTime)
+	}
+
+	// Only count requests that went through a provider (provider_id > 0)
+	q = q.Where("provider_id > 0")
+
+	var result struct {
+		TotalRequests   int64
+		SuccessRequests int64
+	}
+
+	if err := q.Select(`
+		COUNT(*) as total_requests,
+		SUM(CASE WHEN status_code >= 200 AND status_code < 400 THEN 1 ELSE 0 END) as success_requests
+	`).Scan(&result).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to aggregate api key stats from logs", "details": err.Error()})
+		return
+	}
+
+	total := result.TotalRequests
+	success := result.SuccessRequests
+	failure := total - success
+	if failure < 0 {
+		failure = 0
+	}
+
+	var successRate float64
+	var failureRate float64
+	if total > 0 {
+		successRate = float64(success) / float64(total)
+		failureRate = float64(failure) / float64(total)
+	}
+
+	c.JSON(http.StatusOK, APIKeyStatsSummaryResponse{
+		TotalRequests:   total,
+		SuccessRequests: success,
+		FailureRequests: failure,
+		SuccessRate:     successRate,
+		FailureRate:     failureRate,
+	})
+}