feat(claude): add switch for device profile stabilization

internal/config/claude_header_defaults_test.go

@@ -17,6 +17,7 @@ claude-header-defaults:
   os: "  MacOS  "
   arch: "  arm64  "
   timeout: "  900  "
+  stabilize-device-profile: false
 `)
 	if err := os.WriteFile(configPath, configYAML, 0o600); err != nil {
 		t.Fatalf("failed to write config: %v", err)
@@ -45,4 +46,10 @@ claude-header-defaults:
 	if got := cfg.ClaudeHeaderDefaults.Timeout; got != "900" {
 		t.Fatalf("Timeout = %q, want %q", got, "900")
 	}
+	if cfg.ClaudeHeaderDefaults.StabilizeDeviceProfile == nil {
+		t.Fatal("StabilizeDeviceProfile = nil, want non-nil")
+	}
+	if got := *cfg.ClaudeHeaderDefaults.StabilizeDeviceProfile; got {
+		t.Fatalf("StabilizeDeviceProfile = %v, want false", got)
+	}
 }

internal/config/config.go

@@ -131,12 +131,13 @@ type Config struct {
 // ClaudeHeaderDefaults configures default header values injected into Claude API requests
 // when the client does not send them. Update these when Claude Code releases a new version.
 type ClaudeHeaderDefaults struct {
-	UserAgent      string `yaml:"user-agent" json:"user-agent"`
-	PackageVersion string `yaml:"package-version" json:"package-version"`
-	RuntimeVersion string `yaml:"runtime-version" json:"runtime-version"`
-	OS             string `yaml:"os" json:"os"`
-	Arch           string `yaml:"arch" json:"arch"`
-	Timeout        string `yaml:"timeout" json:"timeout"`
+	UserAgent              string `yaml:"user-agent" json:"user-agent"`
+	PackageVersion         string `yaml:"package-version" json:"package-version"`
+	RuntimeVersion         string `yaml:"runtime-version" json:"runtime-version"`
+	OS                     string `yaml:"os" json:"os"`
+	Arch                   string `yaml:"arch" json:"arch"`
+	Timeout                string `yaml:"timeout" json:"timeout"`
+	StabilizeDeviceProfile *bool  `yaml:"stabilize-device-profile,omitempty" json:"stabilize-device-profile,omitempty"`
 }
 
 // CodexHeaderDefaults configures fallback header values injected into Codex