refactor!: rename chat providers to channels

src/agents/tools/agent-step.ts

@@ -1,7 +1,7 @@
 import crypto from "node:crypto";
 
 import { callGateway } from "../../gateway/call.js";
-import { INTERNAL_MESSAGE_PROVIDER } from "../../utils/message-provider.js";
+import { INTERNAL_MESSAGE_CHANNEL } from "../../utils/message-channel.js";
 import { AGENT_LANE_NESTED } from "../lanes.js";
 import { extractAssistantText, stripToolMessages } from "./sessions-helpers.js";
 
@@ -25,7 +25,7 @@ export async function runAgentStep(params: {
   message: string;
   extraSystemPrompt: string;
   timeoutMs: number;
-  provider?: string;
+  channel?: string;
   lane?: string;
 }): Promise<string | undefined> {
   const stepIdem = crypto.randomUUID();
@@ -36,7 +36,7 @@ export async function runAgentStep(params: {
       sessionKey: params.sessionKey,
       idempotencyKey: stepIdem,
       deliver: false,
-      provider: params.provider ?? INTERNAL_MESSAGE_PROVIDER,
+      channel: params.channel ?? INTERNAL_MESSAGE_CHANNEL,
       lane: params.lane ?? AGENT_LANE_NESTED,
       extraSystemPrompt: params.extraSystemPrompt,
     },