fix: honor message tool channel for tool dedupe (#1053)

- Treat message tool `channel` as provider hint for dedupe/suppression.
- Prefer NO_REPLY after message tool sends to avoid duplicate replies.

Co-authored-by: Sash Catanzarite <1166151+thesash@users.noreply.github.com>

src/agents/pi-embedded-subscribe.tools.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from "vitest";
+
+import { extractMessagingToolSend } from "./pi-embedded-subscribe.tools.js";
+
+describe("extractMessagingToolSend", () => {
+  it("uses channel as provider for message tool", () => {
+    const result = extractMessagingToolSend("message", {
+      action: "send",
+      channel: "telegram",
+      to: "123",
+    });
+
+    expect(result?.tool).toBe("message");
+    expect(result?.provider).toBe("telegram");
+    expect(result?.to).toBe("telegram:123");
+  });
+
+  it("prefers provider when both provider and channel are set", () => {
+    const result = extractMessagingToolSend("message", {
+      action: "send",
+      provider: "slack",
+      channel: "telegram",
+      to: "channel:C1",
+    });
+
+    expect(result?.tool).toBe("message");
+    expect(result?.provider).toBe("slack");
+    expect(result?.to).toBe("channel:c1");
+  });
+});