fix(lint): check error return from provider.Close() (#1250)

Two lint errors introduced in recent commits:
- cmd/bd/doctor/git.go:896 - unchecked provider.Close()
- cmd/bd/orphans.go:120 - unchecked provider.Close()

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/doctor/git.go

@@ -893,7 +893,7 @@ func FindOrphanedIssuesFromPath(path string) ([]OrphanIssue, error) {
 	if err != nil {
 		return []OrphanIssue{}, nil
 	}
-	defer provider.Close()
+	defer func() { _ = provider.Close() }()
 
 	return FindOrphanedIssues(path, provider)
 }

cmd/bd/orphans.go

@@ -117,7 +117,7 @@ func getIssueProvider() (types.IssueProvider, func(), error) {
 		if err != nil {
 			return nil, nil, fmt.Errorf("failed to open database at %s: %w", dbPath, err)
 		}
-		return provider, func() { provider.Close() }, nil
+		return provider, func() { _ = provider.Close() }, nil
 	}
 
 	// Use the global store (already opened by PersistentPreRun)