feat(cli): render markdown tables and formatting in non-streaming responses

[crazywriter1]

Summary

Fixes #3621 - CLI now renders markdown (tables, headings, code blocks, lists) properly in non-streaming mode instead of displaying raw syntax like | header | header |.

Changes

• Added _looks_like_markdown() heuristic that detects markdown content by checking for 2+ indicators (tables, headings, fenced code blocks, ordered/unordered lists)
• Added _render_response_content() that returns rich.Markdown when markdown is detected, falls back to existing _rich_text_from_ansi() for plain text
• Updated all 3 non-streaming Panel render sites:
  • Main response panel (~L6067)
  • Background task response panel (~L4184)
  • /btw side-question response panel (~L4308)

What's NOT changed

• Streaming behavior is untouched, token-by-token rendering remains as-is
• No new dependencies - rich.Markdown is already available via the existing rich>=14.3.3 requirement

Why a heuristic?

Blindly passing every response through rich.Markdown would break plain text and ANSI colored tool output. The 2-indicator threshold avoids false positives (e.g. a line starting with # in a shell command won't trigger markdown rendering on its own).

Test plan

• Syntax check passes
• 10/10 custom heuristic unit tests pass (detection + return type)
• 86/86 existing CLI tests pass (4 pre-existing async failures unrelated to this change)
• Manual verification: send a query that returns a markdown table with stream: false and confirm it renders as a formatted table

Future work

Streaming markdown rendering (#3621 streaming case) is intentionally deferred to a separate PR. It involves UX tradeoffs (buffering vs re-rendering vs incremental parsing) that deserve their own discussion.

[teknium1]

Thanks for the PR, @crazywriter1! This has since been implemented on main in a more complete form.

This is an automated hermes-sweeper review.

What landed on main:

• _render_final_assistant_content() in cli.py (line 1239) supports three modes: render (passes through rich.Markdown — the behavior you added), strip (plain text, the new default), and raw (ANSI passthrough).
• Controlled via display.final_response_markdown: render | strip | raw in hermes_cli/config.py (line 634).
• All three Panel render sites this PR targeted are covered: main response panel, background task panel, and /btw panel — see commits 177e6eb3d and 09ced16e.
• Shipped in release v2026.4.23.

One design difference: the main implementation requires users to opt in with display.final_response_markdown: render rather than auto-detecting markdown. This was intentional to avoid false positives on shell output. If you feel auto-detection is still worth adding on top of this, a new focused PR would be welcome.

Closing as implemented_on_main.