Centralize Git identity environment construction

internal/codex/session.go

@@ -27,8 +27,6 @@ type Options struct {
 	Resume     string
 	ForkFrom   string
 	ForkAt     string
-	GitName    string
-	GitEmail   string
 	Env        []string
 	Guidance   string
 	Reminder   string
@@ -158,7 +156,7 @@ func spawn(opts Options) (*Session, error) {
 	cmd := procgroup.Command("codex", "app-server", "-c", "check_for_update_on_startup=false")
 	cmd.Dir = opts.Cwd
 	cmd.Stderr = os.Stderr
-	cmd.Env = buildEnv(opts)
+	cmd.Env = append(os.Environ(), opts.Env...)
 
 	stdinR, stdin, err := os.Pipe()
 	if err != nil {
@@ -321,16 +319,6 @@ func (s *Session) setThread(id string) {
 	s.stateMu.Unlock()
 }
 
-func buildEnv(opts Options) []string {
-	env := append(os.Environ(),
-		"GIT_AUTHOR_NAME="+opts.GitName,
-		"GIT_AUTHOR_EMAIL="+opts.GitEmail,
-		"GIT_COMMITTER_NAME="+opts.GitName,
-		"GIT_COMMITTER_EMAIL="+opts.GitEmail,
-	)
-	return append(env, opts.Env...)
-}
-
 func (s *Session) Events() <-chan Event {
 	return s.events
 }