Add Codex websocket header defaults

internal/config/codex_websocket_header_defaults_test.go

@@ -0,0 +1,32 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoadConfigOptional_CodexHeaderDefaults(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.yaml")
+	configYAML := []byte(`
+codex-header-defaults:
+  user-agent: "  my-codex-client/1.0  "
+  beta-features: "  feature-a,feature-b  "
+`)
+	if err := os.WriteFile(configPath, configYAML, 0o600); err != nil {
+		t.Fatalf("failed to write config: %v", err)
+	}
+
+	cfg, err := LoadConfigOptional(configPath, false)
+	if err != nil {
+		t.Fatalf("LoadConfigOptional() error = %v", err)
+	}
+
+	if got := cfg.CodexHeaderDefaults.UserAgent; got != "my-codex-client/1.0" {
+		t.Fatalf("UserAgent = %q, want %q", got, "my-codex-client/1.0")
+	}
+	if got := cfg.CodexHeaderDefaults.BetaFeatures; got != "feature-a,feature-b" {
+		t.Fatalf("BetaFeatures = %q, want %q", got, "feature-a,feature-b")
+	}
+}