Problem

Feishu (Lark) post/tag:md renderer cannot parse markdown tables. Sending table content as post causes a blank message on the client. The previous workaround downgraded the entire message to plain text (msg_type: text), losing ALL formatting.

Additionally, Feishu interactive cards without "schema": "2.0" fall back to Schema 1.0, which has severely limited markdown support (no headings, blockquotes, or inline code).

Solution

When a message contains a markdown table, render it as a Schema 2.0 interactive card (white background, full width) with pipe-separated headers and data rows. Non-table content renders natively via the card's tag:markdown element (headings, blockquotes, inline code, code blocks all work in Schema 2.0).

Changes

• _render_table_as_md(): parse markdown tables into pipe-separated text with plain-text headers (no bold - card markdown does not render bold when | pipe chars are on the same line)
• _build_content_card_payload(): wrap content in Schema 2.0 interactive card with wide_screen_mode enabled
• _build_outbound_payload(): tables - interactive card; markdown hints - post/tag:md (unchanged); plain text - text (unchanged)
• send(): fallback chain interactive - post/md - text if API rejects
• _TABLE_SEPARATOR_RE: module-level regex for detecting table separator rows

Testing

All 198 existing Feishu adapter tests continue to pass. Tested interactively on Feishu DM with messages containing tables, headings, blockquotes, inline code, code blocks, bold, links, and lists.