fix(telegram): include forward_from_chat metadata in forwarded message context (#8133)

Extract missing metadata from forwarded Telegram messages:

- Add fromChatType to TelegramForwardedContext, capturing the original
  chat type (channel/supergroup/group) from forward_from_chat.type
  and forward_origin.chat/sender_chat.type
- Add fromMessageId to capture the original message ID from channel forwards
- Read author_signature from forward_origin objects (modern API),
  preferring it over the deprecated forward_signature field
- Pass ForwardedFromChatType and ForwardedFromMessageId through to
  the inbound context payload
- Add test coverage for forward_origin channel/chat types, including
  author_signature extraction and fromChatType propagation

src/auto-reply/templating.ts

@@ -56,6 +56,8 @@ export type MsgContext = {
   ForwardedFromUsername?: string;
   ForwardedFromTitle?: string;
   ForwardedFromSignature?: string;
+  ForwardedFromChatType?: string;
+  ForwardedFromMessageId?: number;
   ForwardedDate?: number;
   ThreadStarterBody?: string;
   ThreadLabel?: string;

src/telegram/bot-message-context.ts

@@ -598,6 +598,8 @@ export const buildTelegramMessageContext = async ({
     ForwardedFromUsername: forwardOrigin?.fromUsername,
     ForwardedFromTitle: forwardOrigin?.fromTitle,
     ForwardedFromSignature: forwardOrigin?.fromSignature,
+    ForwardedFromChatType: forwardOrigin?.fromChatType,
+    ForwardedFromMessageId: forwardOrigin?.fromMessageId,
     ForwardedDate: forwardOrigin?.date ? forwardOrigin.date * 1000 : undefined,
     Timestamp: msg.date ? msg.date * 1000 : undefined,
     WasMentioned: isGroup ? effectiveWasMentioned : undefined,

src/telegram/bot/helpers.test.ts

@@ -100,6 +100,90 @@ describe("normalizeForwardedContext", () => {
     expect(ctx?.fromTitle).toBe("Hidden Name");
     expect(ctx?.date).toBe(456);
   });
+
+  it("handles forward_origin channel with author_signature and message_id", () => {
+    const ctx = normalizeForwardedContext({
+      forward_origin: {
+        type: "channel",
+        chat: {
+          title: "Tech News",
+          username: "technews",
+          id: -1001234,
+          type: "channel",
+        },
+        date: 500,
+        author_signature: "Editor",
+        message_id: 42,
+      },
+      // oxlint-disable-next-line typescript/no-explicit-any
+    } as any);
+    expect(ctx).not.toBeNull();
+    expect(ctx?.from).toBe("Tech News (Editor)");
+    expect(ctx?.fromType).toBe("channel");
+    expect(ctx?.fromId).toBe("-1001234");
+    expect(ctx?.fromUsername).toBe("technews");
+    expect(ctx?.fromTitle).toBe("Tech News");
+    expect(ctx?.fromSignature).toBe("Editor");
+    expect(ctx?.fromChatType).toBe("channel");
+    expect(ctx?.fromMessageId).toBe(42);
+    expect(ctx?.date).toBe(500);
+  });
+
+  it("handles forward_origin chat with sender_chat and author_signature", () => {
+    const ctx = normalizeForwardedContext({
+      forward_origin: {
+        type: "chat",
+        sender_chat: {
+          title: "Discussion Group",
+          id: -1005678,
+          type: "supergroup",
+        },
+        date: 600,
+        author_signature: "Admin",
+      },
+      // oxlint-disable-next-line typescript/no-explicit-any
+    } as any);
+    expect(ctx).not.toBeNull();
+    expect(ctx?.from).toBe("Discussion Group (Admin)");
+    expect(ctx?.fromType).toBe("chat");
+    expect(ctx?.fromId).toBe("-1005678");
+    expect(ctx?.fromTitle).toBe("Discussion Group");
+    expect(ctx?.fromSignature).toBe("Admin");
+    expect(ctx?.fromChatType).toBe("supergroup");
+    expect(ctx?.date).toBe(600);
+  });
+
+  it("uses author_signature from forward_origin", () => {
+    const ctx = normalizeForwardedContext({
+      forward_origin: {
+        type: "channel",
+        chat: { title: "My Channel", id: -100999, type: "channel" },
+        date: 700,
+        author_signature: "New Sig",
+        message_id: 1,
+      },
+      // oxlint-disable-next-line typescript/no-explicit-any
+    } as any);
+    expect(ctx).not.toBeNull();
+    expect(ctx?.fromSignature).toBe("New Sig");
+    expect(ctx?.from).toBe("My Channel (New Sig)");
+  });
+
+  it("handles forward_origin channel without author_signature", () => {
+    const ctx = normalizeForwardedContext({
+      forward_origin: {
+        type: "channel",
+        chat: { title: "News", id: -100111, type: "channel" },
+        date: 900,
+        message_id: 1,
+      },
+      // oxlint-disable-next-line typescript/no-explicit-any
+    } as any);
+    expect(ctx).not.toBeNull();
+    expect(ctx?.from).toBe("News");
+    expect(ctx?.fromSignature).toBeUndefined();
+    expect(ctx?.fromChatType).toBe("channel");
+  });
 });
 
 describe("expandTextLinks", () => {

src/telegram/bot/helpers.ts

@@ -261,6 +261,10 @@ export type TelegramForwardedContext = {
   fromUsername?: string;
   fromTitle?: string;
   fromSignature?: string;
+  /** Original chat type from forward_from_chat (e.g. "channel", "supergroup", "group"). */
+  fromChatType?: string;
+  /** Original message ID in the source chat (channel forwards). */
+  fromMessageId?: number;
 };
 
 function normalizeForwardedUserLabel(user: User) {
@@ -323,6 +327,7 @@ function buildForwardedContextFromChat(params: {
   date?: number;
   type: string;
   signature?: string;
+  messageId?: number;
 }): TelegramForwardedContext | null {
   const fallbackKind = params.type === "channel" ? "channel" : "chat";
   const { display, title, username, id } = normalizeForwardedChatLabel(params.chat, fallbackKind);
@@ -331,6 +336,7 @@ function buildForwardedContextFromChat(params: {
   }
   const signature = params.signature?.trim() || undefined;
   const from = signature ? `${display} (${signature})` : display;
+  const chatType = params.chat.type?.trim() || undefined;
   return {
     from,
     date: params.date,
@@ -339,6 +345,8 @@ function buildForwardedContextFromChat(params: {
     fromUsername: username,
     fromTitle: title,
     fromSignature: signature,
+    fromChatType: chatType,
+    fromMessageId: params.messageId,
   };
 }
 
@@ -369,6 +377,7 @@ function resolveForwardOrigin(origin: MessageOrigin): TelegramForwardedContext |
         date: origin.date,
         type: "channel",
         signature: origin.author_signature,
+        messageId: origin.message_id,
       });
     default:
       // Exhaustiveness guard: if Grammy adds a new MessageOrigin variant,