refactor(idgen): centralize negative ID handling via panic

Restore NextUint64ID() to uint64-only API so callers need no error
checks. Retry logic stays in idgen; after 3 negative values it panics
instead of returning 0, preventing silent NULL primary keys.

internal/apps/admin/user/routers.go

@@ -386,14 +386,8 @@ func CreateUser(c *gin.Context) {
 		return
 	}
 
-	nextID, err := idgen.NextUint64ID()
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, response.Err(createUserFailed))
-		return
-	}
-
 	newUser := model.User{
-		ID:          nextID,
+		ID:          idgen.NextUint64ID(),
 		Username:    req.Username,
 		Nickname:    req.Nickname,
 		Email:       req.Email,

internal/apps/risk_control/middleware.go

@@ -15,7 +15,6 @@ import (
 	"github.com/Rain-kl/Wavelet/internal/db/idgen"
 	"github.com/Rain-kl/Wavelet/internal/model"
 	"github.com/Rain-kl/Wavelet/internal/util"
-	"github.com/Rain-kl/Wavelet/pkg/logger"
 	"github.com/gin-gonic/gin"
 )
 
@@ -70,14 +69,8 @@ func RiskControlMiddleware() gin.HandlerFunc {
 			status = maxHTTPStatus
 		}
 
-		logID, err := idgen.NextUint64ID()
-		if err != nil {
-			logger.ErrorF(c.Request.Context(), "[RiskControl] access log ID generation failed: %v", err)
-			return
-		}
-
 		logItem := &UserAccessLog{
-			ID:        logID,
+			ID:        idgen.NextUint64ID(),
 			UserID:    userObj.ID, // 直接从 Context 获取已登录用户ID，避免数据库查询
 			Path:      c.Request.URL.Path,
 			Method:    c.Request.Method,

internal/apps/upload/routers.go

@@ -140,11 +140,7 @@ func UploadFile(c *gin.Context) {
 		return
 	}
 
-	id, err := idgen.NextUint64ID()
-	if err != nil {
-		c.JSON(http.StatusOK, response.Err(ErrSaveUploadRecordFailed))
-		return
-	}
+	id := idgen.NextUint64ID()
 	subPath := fmt.Sprintf("uploads/%s/%d.%s", time.Now().Format("2006/01/02"), id, ext)
 
 	// 8. 写入当前活动存储驱动。
@@ -376,11 +372,7 @@ func tryInstantUpload(ctx context.Context, c *gin.Context, currUser *model.User,
 		return true, nil
 	}
 
-	id, err := idgen.NextUint64ID()
-	if err != nil {
-		c.JSON(http.StatusOK, response.Err(ErrSaveUploadRecordFailed))
-		return true, err
-	}
+	id := idgen.NextUint64ID()
 	newUpload := model.Upload{
 		ID:            id,
 		UserID:        currUser.ID,

internal/apps/user/routers.go

@@ -228,14 +228,8 @@ func Register(c *gin.Context) {
 		return
 	}
 
-	nextID, err := idgen.NextUint64ID()
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, response.Err(err.Error()))
-		return
-	}
-
 	user := model.User{
-		ID:          nextID,
+		ID:          idgen.NextUint64ID(),
 		Username:    req.Username,
 		Nickname:    req.Nickname,
 		Email:       req.Email,