fix(workspace): tolerate read-only files on delete

Co-Authored-By: Claude <noreply@anthropic.com>

internal/workspace/manager.go

@@ -8,6 +8,25 @@ import (
 	"codespace/internal/util"
 )
 
+
+// forceRemove chmods every file and directory under root to writable before
+// removing the tree. It ignores chmod and walk errors so that partial or
+// concurrent removals do not abort the delete.
+func forceRemove(root string) error {
+	_ = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
+		if err != nil {
+			return nil
+		}
+		mode := os.FileMode(0o644)
+		if d.IsDir() {
+			mode = 0o755
+		}
+		_ = os.Chmod(path, mode)
+		return nil
+	})
+	return os.RemoveAll(root)
+}
+
 // Manager manages workspace lifecycle.
 type Manager interface {
 	Create(id string) (*Workspace, error)
@@ -68,7 +87,7 @@ func (m *LocalManager) Delete(id string) error {
 		return util.New(util.CodeBadRequest, "invalid workspace id")
 	}
 	root := RootFor(m.root, id)
-	if err := os.RemoveAll(root); err != nil {
+	if err := forceRemove(root); err != nil {
 		return util.Wrap(util.CodeInternal, "failed to delete workspace", err)
 	}
 	return nil