fix: guard markdownToHtml in the HTML fallback path

A throw from the converter used to escape the try/catch and drop the
message; degrade to plain text for that chunk instead.

lib/bridge.js

@@ -828,7 +828,13 @@ export class TelegramBridge {
     async deliverHtml(chatId, markdown) {
         const chunks = splitMessage(markdown, this.maxMessageLength);
         for (const chunk of chunks) {
-            const html = markdownToHtml(chunk);
+            let html;
+            try {
+                html = markdownToHtml(chunk);
+            }
+            catch {
+                html = chunk; // Pathological markdown input: degrade to plain text instead of dropping.
+            }
             try {
                 await this.withRetry(() => this.client.sendMessage(chatId, html, 'HTML'));
             }

src/bridge.ts

@@ -954,7 +954,12 @@ export class TelegramBridge {
   private async deliverHtml(chatId: number, markdown: string): Promise<void> {
     const chunks = splitMessage(markdown, this.maxMessageLength)
     for (const chunk of chunks) {
-      const html = markdownToHtml(chunk)
+      let html: string
+      try {
+        html = markdownToHtml(chunk)
+      } catch {
+        html = chunk // Pathological markdown input: degrade to plain text instead of dropping.
+      }
       try {
         await this.withRetry(() => this.client.sendMessage(chatId, html, 'HTML'))
       } catch {