fix(extensions): synthesize mediaLocalRoots propagation across sendMedia adapters

Restore deterministic mediaLocalRoots propagation through extension sendMedia adapters and add coverage for local/remote media handling in Google Chat.

Synthesis of #33581, #33545, #33540, #33536, #33528.

Co-authored-by: bmendonca3 <bmendonca3@users.noreply.github.com>

extensions/whatsapp/src/channel.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it, vi } from "vitest";
+import { whatsappPlugin } from "./channel.js";
+
+describe("whatsappPlugin outbound sendMedia", () => {
+  it("forwards mediaLocalRoots to sendMessageWhatsApp", async () => {
+    const sendWhatsApp = vi.fn(async () => ({
+      messageId: "msg-1",
+      toJid: "15551234567@s.whatsapp.net",
+    }));
+    const mediaLocalRoots = ["/tmp/workspace"];
+
+    const outbound = whatsappPlugin.outbound;
+    if (!outbound?.sendMedia) {
+      throw new Error("whatsapp outbound sendMedia is unavailable");
+    }
+
+    const result = await outbound.sendMedia({
+      cfg: {} as never,
+      to: "whatsapp:+15551234567",
+      text: "photo",
+      mediaUrl: "/tmp/workspace/photo.png",
+      mediaLocalRoots,
+      accountId: "default",
+      deps: { sendWhatsApp },
+      gifPlayback: false,
+    });
+
+    expect(sendWhatsApp).toHaveBeenCalledWith(
+      "whatsapp:+15551234567",
+      "photo",
+      expect.objectContaining({
+        verbose: false,
+        mediaUrl: "/tmp/workspace/photo.png",
+        mediaLocalRoots,
+        accountId: "default",
+        gifPlayback: false,
+      }),
+    );
+    expect(result).toMatchObject({ channel: "whatsapp", messageId: "msg-1" });
+  });
+});

extensions/whatsapp/src/channel.ts

@@ -295,11 +295,12 @@ export const whatsappPlugin: ChannelPlugin<ResolvedWhatsAppAccount> = {
       });
       return { channel: "whatsapp", ...result };
     },
-    sendMedia: async ({ to, text, mediaUrl, accountId, deps, gifPlayback }) => {
+    sendMedia: async ({ to, text, mediaUrl, mediaLocalRoots, accountId, deps, gifPlayback }) => {
       const send = deps?.sendWhatsApp ?? getWhatsAppRuntime().channel.whatsapp.sendMessageWhatsApp;
       const result = await send(to, text, {
         verbose: false,
         mediaUrl,
+        mediaLocalRoots,
         accountId: accountId ?? undefined,
         gifPlayback,
       });