Summary

• route Feishu/Lark markdown replies containing GFM-style tables to Card JSON 2.0 interactive messages
• render table rows as CardKit table elements instead of forcing the whole reply to plain text
• keep non-table markdown replies on the existing post-message path
• add regression coverage for table detection/routing and regular markdown behavior

Motivation

Feishu post messages do not reliably render Markdown tables. The previous workaround forced any reply containing a table to plain text, which preserved the raw content but stripped normal Markdown formatting and left tables unrendered.

This keeps the existing post path for normal Markdown while using an interactive card only when a markdown table is detected.

Fixes #25452
Refs #23938, #27469, #26658, #27695

Test plan

python -m pytest tests/gateway/test_feishu.py -q

Result locally:

200 passed, 2 warnings