Fix SKILL.md validate bug

Author: Dev Agent

component/checker/skill_file_checker.go

@@ -0,0 +1,82 @@
+package checker
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"opencsg.com/csghub-server/builder/git"
+	"opencsg.com/csghub-server/builder/git/gitserver"
+	"opencsg.com/csghub-server/builder/store/database"
+	"opencsg.com/csghub-server/common/config"
+	"opencsg.com/csghub-server/common/types"
+)
+
+type SkillFileChecker struct {
+	repoStore database.RepoStore
+	gitServer gitserver.GitServer
+	config    *config.Config
+}
+
+func NewSkillFileChecker(config *config.Config) (GitCallbackChecker, error) {
+	git, err := git.NewGitServer(config)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create git server: %w", err)
+	}
+	return &SkillFileChecker{
+		repoStore: database.NewRepoStore(),
+		gitServer: git,
+		config:    config,
+	}, nil
+}
+
+func (c *SkillFileChecker) Check(ctx context.Context, req types.GitalyAllowedReq) (bool, error) {
+	var ref string
+	repoType, namespace, name := req.GetRepoTypeNamespaceAndName()
+
+	// Only check skill repositories
+	if repoType != types.SkillRepo {
+		return true, nil
+	}
+
+	repo, err := c.repoStore.FindByPath(ctx, repoType, namespace, name)
+	if err != nil {
+		return false, fmt.Errorf("failed to find repo, err: %v", err)
+	}
+	if repo == nil {
+		return false, errors.New("repo not found")
+	}
+	changes := strings.Split(req.Changes, " ")
+	if len(changes) > 1 {
+		ref = changes[1]
+	}
+
+	// Check if SKILL.md exists and has required metadata in the new content
+	skillsContent, err := c.gitServer.GetRepoFileRaw(ctx, gitserver.GetRepoInfoByPathReq{
+		Namespace:                             namespace,
+		Name:                                  name,
+		RepoType:                              repoType,
+		GitObjectDirectoryRelative:            req.GitEnv.GitObjectDirectoryRelative,
+		GitAlternateObjectDirectoriesRelative: req.GitEnv.GitAlternateObjectDirectoriesRelative,
+		Path:                                  "SKILL.md",
+		Ref:                                   ref,
+	})
+	if err != nil {
+		// SKILL.md not found in new content, reject push
+		return false, fmt.Errorf("skill repository must have a SKILL.md file with name and description metadata")
+	}
+
+	// Check if SKILL.md is in the correct YAML format with name and description
+	pattern := `^---\s*\nname:\s*.+\s*\ndescription:\s*.+\s*---*.`
+	matched, err := regexp.MatchString(pattern, skillsContent)
+	if err != nil {
+		return false, fmt.Errorf("failed to check SKILL.md format: %w", err)
+	}
+	if !matched {
+		return false, fmt.Errorf("SKILL.md must be in YAML format with name and description fields")
+	}
+
+	return true, nil
+}