refactor: trim gateway local type exports

src/gateway/channel-health-monitor.ts

@@ -23,13 +23,13 @@ const ONE_HOUR_MS = 60 * 60_000;
  * Providers should only publish that timestamp from transport/heartbeat/poll
  * signals, not from ordinary app messages.
  */
-export type ChannelHealthTimingPolicy = {
+type ChannelHealthTimingPolicy = {
   monitorStartupGraceMs: number;
   channelConnectGraceMs: number;
   staleEventThresholdMs: number;
 };
 
-export type ChannelHealthMonitorDeps = {
+type ChannelHealthMonitorDeps = {
   channelManager: ChannelManager;
   checkIntervalMs?: number;
   /** @deprecated use timing.monitorStartupGraceMs */

src/gateway/chat-abort.ts

@@ -20,7 +20,7 @@ export type ChatAbortControllerEntry = {
   kind?: "chat-send" | "agent";
 };
 
-export type RegisteredChatAbortController = {
+type RegisteredChatAbortController = {
   controller: AbortController;
   registered: boolean;
   entry?: ChatAbortControllerEntry;

src/gateway/credentials.ts

@@ -17,7 +17,7 @@ export type ExplicitGatewayAuth = {
   password?: string;
 };
 
-export type ResolvedGatewayCredentials = {
+type ResolvedGatewayCredentials = {
   token?: string;
   password?: string;
 };