fix(feishu): remove faulty table→text fallback in outbound payload

[wowpigpan]

Summary

The _build_outbound_payload function was downgrading messages containing markdown tables from post type (rich rendering) to text type (raw text). This caused all markdown formatting to appear as raw source when a table was present.

Root Cause

The function checked for markdown tables first and forced the entire message to text msg_type. Feishu clients now render tables correctly in post type via the md element.

Fix

Removed the table-detection fallback. Messages with markdown (including tables) now use post type. Plain text uses text type.

Test Plan

• Tested on Feishu 7.x (macOS): bold, italic, headings, code blocks, inline code, blockquotes, lists, and tables all render correctly

[alt-glitch]

Duplicate of #26108 — both remove the faulty _MARKDOWN_TABLE_RE force-text fallback in Feishu _build_outbound_payload. Part of long-standing issue family: #9549, #21866, #25452, #26658. Also competes with #27922.

[teknium1]

Thanks for the focused Feishu report. The force-text behavior is still present, but this patch needs a small re-scope before it can affect current main.

Problems

• Current main moved the active adapter from gateway/platforms/feishu.py to plugins/platforms/feishu/adapter.py in 560010547; the PR changes only the removed path.
• Removing the early return alone does not make a bare table a post: _MARKDOWN_HINT_RE at plugins/platforms/feishu/adapter.py:154-157 has no table alternative, so the final text return at :4533-4534 still applies.
• The patch has no regression test for table-only routing.

Suggested changes

• Apply the change to plugins/platforms/feishu/adapter.py and route table-regex matches through _build_markdown_post_payload() alongside markdown hints.
• Add tests/gateway/test_feishu.py coverage for bare-table and mixed markdown-plus-table post routing, with a plain-text control.

This is an automated hermes-sweeper review.

[teknium1]

This file is no longer the active adapter on current main (560010547 moved it to plugins/platforms/feishu/adapter.py). Also, removing the force-text branch without adding table syntax to the post-routing predicate leaves a bare table at the final text return; salvage this by routing _MARKDOWN_TABLE_RE matches to post in the plugin and add a bare-table regression test.