Parse markdown formatting (bold, italic, strikethrough, headings, lists,
code blocks, blockquotes, custom color/style tags) into Zalo native
TextStyle ranges so outbound messages render with rich formatting.
- Add text-styles.ts with parseZalouserTextStyles() converter
- Wire markdown mode into send pipeline (sendMessageZalouser)
- Export TextStyle enum and Style type from zca-client
- Add textMode/textStyles to ZaloSendOptions
- Pass textStyles through sendZaloTextMessage to zca-js API
- Enable textMode:"markdown" in outbound sendText/sendMedia and monitor
- Add comprehensive tests for parsing, send, and channel integration
99c43e7d05