Telegram/Discord: honor outbound mediaMaxMb uploads (#38065)

* Telegram: default media cap to 100MB

* Telegram: honor outbound mediaMaxMb

* Discord: add shared media upload cap

* Discord: pass mediaMaxMb to outbound sends

* Telegram: cover outbound media cap sends

* Discord: cover media upload cap config

* Docs: update Telegram media cap guide

* Docs: update Telegram config reference

* Changelog: note media upload cap fix

* Docs: note Discord upload cap behavior

src/telegram/send.test.ts

@@ -1149,6 +1149,69 @@ describe("sendMessageTelegram", () => {
     });
     expect(res.messageId).toBe("59");
   });
+
+  it("defaults outbound media uploads to 100MB", async () => {
+    const chatId = "123";
+    const sendPhoto = vi.fn().mockResolvedValue({
+      message_id: 60,
+      chat: { id: chatId },
+    });
+    const api = { sendPhoto } as unknown as {
+      sendPhoto: typeof sendPhoto;
+    };
+
+    mockLoadedMedia({
+      buffer: Buffer.from("fake-image"),
+      contentType: "image/jpeg",
+      fileName: "photo.jpg",
+    });
+
+    await sendMessageTelegram(chatId, "photo", {
+      token: "tok",
+      api,
+      mediaUrl: "https://example.com/photo.jpg",
+    });
+
+    expect(loadWebMedia).toHaveBeenCalledWith(
+      "https://example.com/photo.jpg",
+      expect.objectContaining({ maxBytes: 100 * 1024 * 1024 }),
+    );
+  });
+
+  it("uses configured telegram mediaMaxMb for outbound uploads", async () => {
+    const chatId = "123";
+    const sendPhoto = vi.fn().mockResolvedValue({
+      message_id: 61,
+      chat: { id: chatId },
+    });
+    const api = { sendPhoto } as unknown as {
+      sendPhoto: typeof sendPhoto;
+    };
+    loadConfig.mockReturnValue({
+      channels: {
+        telegram: {
+          mediaMaxMb: 42,
+        },
+      },
+    });
+
+    mockLoadedMedia({
+      buffer: Buffer.from("fake-image"),
+      contentType: "image/jpeg",
+      fileName: "photo.jpg",
+    });
+
+    await sendMessageTelegram(chatId, "photo", {
+      token: "tok",
+      api,
+      mediaUrl: "https://example.com/photo.jpg",
+    });
+
+    expect(loadWebMedia).toHaveBeenCalledWith(
+      "https://example.com/photo.jpg",
+      expect.objectContaining({ maxBytes: 42 * 1024 * 1024 }),
+    );
+  });
 });
 
 describe("reactMessageTelegram", () => {