Centralize Git identity environment construction

internal/claude/session.go

@@ -35,8 +35,6 @@ type Options struct {
 	Resume      string
 	ResumeAt    string
 	ForkSession bool
-	GitName     string
-	GitEmail    string
 	Env         []string
 	Guidance    string
 	Hooks       map[string][]HookMatcher
@@ -370,10 +368,6 @@ func buildEnv(opts Options) []string {
 	env = append(env,
 		"CLAUDE_CODE_ENTRYPOINT=sdk-go",
 		"CLAUDE_CODE_DISABLE_AUTOUPDATER=1",
-		"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...)
 }