use html as telegram bot parse mode

app/lib/tasks/telegram_bot_task.rb

@@ -125,7 +125,7 @@ module Tasks
           chat_id: chat_id,
           message_id: response_message.message_id,
           text: result_text,
-          parse_mode: "Markdown",
+          parse_mode: "HTML",
         )
 
         # Record total request time
@@ -386,9 +386,10 @@ module Tasks
 
           external_url = post.external_url_for_view
           if (title = post.title) && external_url
-            response += " - [#{post.to_param} - #{title}](#{external_url})"
+            response +=
+              " - <a href=\"#{external_url}\">#{post.to_param} - #{html_escape(title)}</a>"
           elsif external_url
-            response += " - [#{post.to_param}](#{external_url})"
+            response += " - <a href=\"#{external_url}\">#{post.to_param}</a>"
           else
             response += " - #{post.to_param}"
           end
@@ -396,9 +397,10 @@ module Tasks
           if post.respond_to?(:creator) && (creator = post.send(:creator))
             url = creator.external_url_for_view
             if url
-              response += " by [#{creator.name_for_view}](#{url})"
+              response +=
+                " by <a href=\"#{url}\">#{html_escape(creator.name_for_view)}</a>"
             else
-              response += " by #{creator.name_for_view}"
+              response += " by #{html_escape(creator.name_for_view)}"
             end
           end
           response += "\n"
@@ -407,6 +409,17 @@ module Tasks
       response
     end
 
+    sig { params(text: String).returns(String) }
+    def html_escape(text)
+      # Only escape characters that are explicitly required by Telegram Bot API
+      # All <, > and & symbols that are not part of a tag or HTML entity must be replaced
+      # API supports only these named HTML entities: &lt;, &gt;, &amp; and &quot;
+      text
+        .gsub("&", "&amp;") # Ampersand (must be first to avoid double-escaping)
+        .gsub("<", "&lt;") # Less than
+        .gsub(">", "&gt;") # Greater than
+    end
+
     # Extract image file information from Telegram message
     sig do
       params(message: Telegram::Bot::Types::Message).returns(