Bot API bridge plug-in

Key features

• The assistant text is converted according to a conservative subset of Markdown (fence code → , inline code → , bold → , and the rest HTML escaped), and fragmented according to maxMessageLength, giving priority to line breaks at newlines, Chinese periods, and periods + spaces.
• When Telegram rejects the HTML body (the entity is incomplete after fragmentation), the fragment falls back to sending plain text.
• turn/start sends typing chat action
• Delivery is fire-and-forget, logging piece by piece.
• A single long polling loop serves all chats