chore(lint): unify formatting on golangci-lint fmt (gofumpt), uncap issue reporting, fix gofumpt drift

- make format 现在与 code-check 使用同一格式化器（golangci-lint fmt），消除 goimports -local 与 gofumpt 的格式拉锯
- .golangci.yml 关闭默认 50/3 截断，完整上报所有问题（只增强不弱化）
- 全库 gofumpt 规范化（203 files, 纯格式无行为变更）

backend/core/extpoints/extpoints_test.go

@@ -4,6 +4,8 @@
 package extpoints_test
 
 import (
+	"Wavelet/core"
+	"Wavelet/core/extpoints"
 	"context"
 	"testing"
 	"testing/fstest"
@@ -11,9 +13,6 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-
-	"Wavelet/core"
-	"Wavelet/core/extpoints"
 )
 
 func TestRouterExtension(t *testing.T) {

backend/core/extpoints/router.go

@@ -21,7 +21,7 @@ type RouteDefinition struct {
 type RouterExtension interface {
 	Use(middlewares ...any)
 	Group(prefix string, middlewares ...any) RouterExtension
-	Handle(method string, path string, handlers ...any) RouteDefinition
+	Handle(method, path string, handlers ...any) RouteDefinition
 	GET(path string, handlers ...any) RouteDefinition
 	POST(path string, handlers ...any) RouteDefinition
 	PUT(path string, handlers ...any) RouteDefinition

backend/core/extpoints/schedule.go

@@ -28,8 +28,8 @@ func WithScheduleOption(key string, val any) ScheduleOption {
 
 // ScheduleExtension defines the interface for registering and querying cron/scheduled tasks.
 type ScheduleExtension interface {
-	Register(spec string, taskType string, payload any, opts ...ScheduleOption)
-	RegisterCron(spec string, taskType string, payload any, opts ...ScheduleOption)
+	Register(spec, taskType string, payload any, opts ...ScheduleOption)
+	RegisterCron(spec, taskType string, payload any, opts ...ScheduleOption)
 	Schedules() []ScheduleDefinition
 	Get(taskType string) (ScheduleDefinition, bool)
 	Unregister(taskType string) bool
@@ -50,7 +50,7 @@ func NewScheduleRegistry() *ScheduleRegistry {
 }
 
 // Register adds a schedule definition.
-func (s *ScheduleRegistry) Register(spec string, taskType string, payload any, opts ...ScheduleOption) {
+func (s *ScheduleRegistry) Register(spec, taskType string, payload any, opts ...ScheduleOption) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
@@ -82,7 +82,7 @@ func (s *ScheduleRegistry) Register(spec string, taskType string, payload any, o
 }
 
 // RegisterCron is an alias for Register.
-func (s *ScheduleRegistry) RegisterCron(spec string, taskType string, payload any, opts ...ScheduleOption) {
+func (s *ScheduleRegistry) RegisterCron(spec, taskType string, payload any, opts ...ScheduleOption) {
 	s.Register(spec, taskType, payload, opts...)
 }