fork of prime agent with changes i want but are not upstreamable probqbly (and some fixes)

fix(tui): format all six markdown heading levels (#2324) master

renderToken() re-attached the raw # prefix for heading levels >= 3, so ### through ###### showed as raw markdown instead of headings. every level now renders as a real heading with a visual taper: h1 bold+ underline, h2/h3 bold, h4 bold+italic, h5/h6 italic. also prefix showError output with the warning icon, matching the existing showWarning treatment. Fixes ENG-6159


+71 -4
6 changed files