feat(telegram): add DeleteMessage API method

Adds Bot.DeleteMessage(chatID, messageID) for deleting bot messages.
Useful for cleanup — removing 'queued' notices, trace messages,
and stale responses. Wired into testServer for handler tests.

Author: molty3000

internal/telegram/bot.go

@@ -293,6 +293,16 @@ func (b *Bot) EditMessageText(chatID int64, messageID int, text string, opts *Se
 	return b.doJSON("editMessageText", params, nil)
 }
 
+// DeleteMessage deletes a message previously sent by the bot.
+// Requires the bot to have can_delete_messages permission in groups/supergroups.
+func (b *Bot) DeleteMessage(chatID int64, messageID int) error {
+	params := map[string]any{
+		"chat_id":    chatID,
+		"message_id": messageID,
+	}
+	return b.doJSON("deleteMessage", params, nil)
+}
+
 // SendPhoto sends a photo from a file path to the specified chat.
 // opts may contain ReplyToMessageID to reply to a specific message.
 func (b *Bot) SendPhoto(chatID int64, path string, caption string, opts *SendOpts) (*Message, error) {

internal/telegram/bot_test.go

@@ -1090,6 +1090,56 @@ func TestBot_EditMessageText_Error(t *testing.T) {
 	}
 }
 
+// ---------------------------------------------------------------------------
+// DeleteMessage
+// ---------------------------------------------------------------------------
+
+func TestBot_DeleteMessage_Success(t *testing.T) {
+	var gotBody map[string]any
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		path := strings.TrimSuffix(r.URL.Path, "/")
+		if path != "/deleteMessage" {
+			t.Errorf("unexpected path: %s", path)
+		}
+		requireJSONBody(t, r, "application/json", &gotBody)
+		okResponse(w, true)
+	}))
+	defer ts.Close()
+
+	bot := NewBot("x")
+	bot.BaseURL = ts.URL
+
+	err := bot.DeleteMessage(123, 456)
+	if err != nil {
+		t.Fatalf("DeleteMessage: %v", err)
+	}
+
+	if gotBody["chat_id"] != float64(123) {
+		t.Errorf("chat_id = %v, want 123", gotBody["chat_id"])
+	}
+	if gotBody["message_id"] != float64(456) {
+		t.Errorf("message_id = %v, want 456", gotBody["message_id"])
+	}
+}
+
+func TestBot_DeleteMessage_Error(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		failResponse(w, 400, "Bad Request: message to delete not found")
+	}))
+	defer ts.Close()
+
+	bot := NewBot("x")
+	bot.BaseURL = ts.URL
+
+	err := bot.DeleteMessage(1, 999)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "message to delete not found") {
+		t.Errorf("error = %q, want substring %q", err, "message to delete not found")
+	}
+}
+
 // ---------------------------------------------------------------------------
 // SetFallbackURLs
 // ---------------------------------------------------------------------------

internal/telegram/handler_test.go

@@ -45,6 +45,8 @@ func testServer(t *testing.T, recorder *requestRecorder) *httptest.Server {
 		switch {
 		case strings.HasSuffix(r.URL.Path, "/answerCallbackQuery"):
 			resp = map[string]any{"ok": true}
+		case strings.HasSuffix(r.URL.Path, "/deleteMessage"):
+			resp = map[string]any{"ok": true}
 		case strings.HasSuffix(r.URL.Path, "/sendMessage"):
 			resp = map[string]any{
 				"ok": true,