Refactor blog post logic to standardize field names and improve error handling; implement pagination for post listing and add tag retrieval functionality.

app/internal/logic/pinglogic.go

@@ -26,6 +26,6 @@ func NewPingLogic(ctx context.Context, svcCtx *svc.ServiceContext) *PingLogic {
 
 func (l *PingLogic) Ping(req *types.PingReq) (resp *types.PingResp, err error) {
 	return &types.PingResp{
-		Ok: true,
+		OK: true,
 	}, nil
 }