chore: misc go 1.27 tweaks (#39069)

Follow-up to https://github.com/go-gitea/gitea/pull/39068, which
disabled `modernize` entirely.

- re-enable `modernize`, with only the new `embedlit` rule disabled. It
flattens embedded struct literals across ~145 files, and orphans imports
in 6 of them that the fixer does not remove
- apply the rest of the suite: `errors.AsType`, `reflect.TypeAssert`,
`strings.Cut`, and dropping the legacy import comment
- use the new stdlib `uuid` package, `github.com/google/uuid` becomes
indirect
- use `strings.CutLast` in place of manual `LastIndex` slicing in label
scopes, email domains and the diff tree list
- take the header lint skip dirs from the `go.mod` `ignore` directive
and skip dot-directories, instead of hardcoding the list

Assisted-by: Claude Code:claude-opus-5

models/auth/oauth2.go

@@ -14,6 +14,7 @@ import (
 	"slices"
 	"strings"
 	"time"
+	"uuid"
 
 	"gitea.dev/models/db"
 	"gitea.dev/modules/container"
@@ -21,7 +22,6 @@ import (
 	"gitea.dev/modules/timeutil"
 	"gitea.dev/modules/util"
 
-	uuid "github.com/google/uuid"
 	"golang.org/x/crypto/bcrypt"
 	"golang.org/x/oauth2"
 	"xorm.io/builder"

models/issues/label.go

@@ -186,11 +186,11 @@ func (l *Label) ExclusiveScope() string {
 	if !l.Exclusive {
 		return ""
 	}
-	lastIndex := strings.LastIndex(l.Name, "/")
-	if lastIndex == -1 || lastIndex == 0 || lastIndex == len(l.Name)-1 {
+	scope, name, found := strings.CutLast(l.Name, "/")
+	if !found || scope == "" || name == "" {
 		return ""
 	}
-	return l.Name[:lastIndex]
+	return scope
 }
 
 // CompareLabelForDisplay compares labels for displaying them in dropdowns or lists.

models/repo/repo_list.go

@@ -617,7 +617,7 @@ func searchRepositoryByCondition(ctx context.Context, opts SearchRepoOptions, co
 		args = append(args, opts.PriorityOwnerID)
 	} else if strings.Count(opts.Keyword, "/") == 1 {
 		// With "owner/repo" search times, prioritise results which match the owner field
-		orgName := strings.Split(opts.Keyword, "/")[0]
+		orgName, _, _ := strings.Cut(opts.Keyword, "/")
 		orderBy = db.SearchOrderBy(fmt.Sprintf("CASE WHEN owner_name LIKE ? THEN 0 ELSE 1 END, %s", orderBy))
 		args = append(args, orgName)
 	}

models/repo/upload.go

@@ -11,13 +11,12 @@ import (
 	"mime/multipart"
 	"os"
 	"path/filepath"
+	"uuid"
 
 	"gitea.dev/models/db"
 	"gitea.dev/modules/log"
 	"gitea.dev/modules/setting"
 	"gitea.dev/modules/util"
-
-	gouuid "github.com/google/uuid"
 )
 
 // ErrUploadNotExist represents a "UploadNotExist" kind of error.
@@ -60,7 +59,7 @@ func (upload *Upload) LocalPath() string {
 // NewUpload creates a new upload object.
 func NewUpload(ctx context.Context, name string, buf []byte, file multipart.File) (_ *Upload, err error) {
 	upload := &Upload{
-		UUID: gouuid.New().String(),
+		UUID: uuid.New().String(),
 		Name: name,
 	}
 

models/webhook/hooktask.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"errors"
 	"time"
+	"uuid"
 
 	"gitea.dev/models/db"
 	"gitea.dev/modules/json"
@@ -15,7 +16,6 @@ import (
 	"gitea.dev/modules/timeutil"
 	webhook_module "gitea.dev/modules/webhook"
 
-	gouuid "github.com/google/uuid"
 	"xorm.io/builder"
 )
 
@@ -119,7 +119,7 @@ func HookTasks(ctx context.Context, hookID int64, page int) ([]*HookTask, error)
 // CreateHookTask creates a new hook task,
 // it handles conversion from Payload to PayloadContent.
 func CreateHookTask(ctx context.Context, t *HookTask) (*HookTask, error) {
-	t.UUID = gouuid.New().String()
+	t.UUID = uuid.New().String()
 	if t.Delivered == 0 {
 		t.Delivered = timeutil.TimeStampNanoNow()
 	}

models/webhook/webhook_test.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"testing"
 	"time"
+	"uuid"
 
 	"gitea.dev/models/db"
 	"gitea.dev/models/unittest"
@@ -15,7 +16,6 @@ import (
 	"gitea.dev/modules/timeutil"
 	webhook_module "gitea.dev/modules/webhook"
 
-	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"xorm.io/builder"