Owners and moderators get a 44 px menu button on each other person's chat line that opens the moderator menu; Escape or an outside tap closes it #385

From #198, piece 2 of 2.

Done:

• [ ] Software/so101/src/ui/lobby-panel.js draws, beside the existing Report button, a menu button (aria-label naming the author, at least 44x44 px, room reserved so no line shifts) on lines where menuItems from src/ui/mod-menu.js is non-empty, and opens renderMenu beneath it. Picking an item sends frameFor(...) over /live and closes the menu; Escape or an outside tap closes it.
• [ ] src/ui/lobby-panel.test.ts checks the button is absent for plain users and on your own line, and that picking Mute 1h sends {type:'mute',id,on:true,for:'1h'}.
• [ ] The first-visit gzip budget test still passes. bun --cwd Software/so101 test passes.