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/plugins/domain/auth/auth_source_resolver.go

@@ -4,14 +4,13 @@
 package auth
 
 import (
+	"Wavelet/core/contracts"
 	"context"
 	"errors"
 	"fmt"
 	"strconv"
 	"strings"
 
-	"Wavelet/core/contracts"
-
 	"github.com/coreos/go-oidc/v3/oidc"
 	"golang.org/x/oauth2"
 )
@@ -128,7 +127,7 @@ func containsScope(scopes []string, scope string) bool {
 	return false
 }
 
-func buildOAuthUserInfo(ctx context.Context, source *AuthSource, code string, nonce string, redirectURL string) (*contracts.OAuthUserInfoDTO, error) {
+func buildOAuthUserInfo(ctx context.Context, source *AuthSource, code, nonce, redirectURL string) (*contracts.OAuthUserInfoDTO, error) {
 	authConfig, verifier, err := buildOAuthConfig(ctx, source, redirectURL)
 	if err != nil {
 		return nil, err