Chat SDK adds table rendering and streaming markdown

Chat SDK introduces native table rendering and improved real-time streaming markdown formatting across all platform adapters.

• •The new Table() component provides a composable API accepting headers and rows, which each platform adapter converts to its native format
• •Slack renders tables as Block Kit table blocks, Teams and Discord use GFM markdown tables, Google Chat uses monospace text widgets, and Telegram converts tables to code blocks
• •GitHub and Linear already supported tables through their markdown pipelines and continue working as before
• •Slack's native streaming path now renders bold, italic, lists, and other formatting in real time as responses arrive, rather than waiting for message completion
• •Other adapters now pass streamed text through the markdown-to-native conversion pipeline at each intermediate edit, fixing the issue where users saw raw markdown syntax like **bold** until the final message