fix(whatsapp): keep opening text chunk when first media fails on multi-chunk reply

When a WhatsApp auto-reply spans more than one chunk and is sent with an image
whose send fails, the first chunk was silently dropped. The first-media onError
fallback evaluated remainingText.shift() before the caption, so on a multi-chunk
reply the truthy second chunk discarded the caption that held the opening chunk.
Resurface the caption directly; the trailing loop already sends the rest.

Adds a regression test driving deliverWebReply with a two-chunk reply and a
failing first media send.

extensions/whatsapp/src/auto-reply/deliver-reply.test.ts

@@ -624,6 +624,32 @@ describe("deliverWebReply", () => {
     expect(warnContext.mediaUrl).toBe("http://example.com/img.jpg");
   });
 
+  it("delivers the opening text chunk when the first media fails on a multi-chunk reply", async () => {
+    const msg = makeMsg();
+    mockLoadedImageMedia();
+    mockFirstSendMediaFailure(msg, "boom");
+
+    await deliverWebReply({
+      replyResult: { text: "ALPHALINEBRAVOLINE", mediaUrl: "http://example.com/img.jpg" },
+      msg,
+      maxMediaBytes: 1024 * 1024,
+      textLimit: 9,
+      replyLogger,
+      skipLog: true,
+    });
+
+    expect(replyText(msg, 0)).toContain("ALPHALINE");
+    expect(replyText(msg, 0)).toContain("⚠️ Media failed");
+    const allReplies = (
+      msg.platform.reply as unknown as { mock: { calls: unknown[][] } }
+    ).mock.calls
+      .map((call) => String(call[0]))
+      .join("\n");
+    expect(allReplies).toContain("ALPHALINE");
+    expect(allReplies).toContain("BRAVOLINE");
+    expect(allReplies).not.toContain("boom");
+  });
+
   it("still attempts later media after the first media fails", async () => {
     vi.clearAllMocks();
     const msg = makeMsg();

extensions/whatsapp/src/auto-reply/deliver-reply.ts

@@ -340,7 +340,7 @@ export async function deliverWebReply(params: {
         return;
       }
       const warning = "⚠️ Media failed.";
-      const fallbackTextParts = [remainingText.shift() ?? caption ?? "", warning].filter(Boolean);
+      const fallbackTextParts = [caption ?? "", warning].filter(Boolean);
       const fallbackText = fallbackTextParts.join("\n");
       if (!fallbackText) {
         return;