The long-press moderation dialog offers Mute (with its length) and Ban to a verified moderator on a plain user's line, not only to the owner #400

Replaces #386. The long-press (480 ms, 10 px) dialog is already on main in src/ui/lobby-panel.js and opens for owners and moderators, but it hides Mute and Ban from moderators although /live accepts both from them (1009636, 81fbc14). #386 asked for a new menu module; this fixes the one that exists and waits on nothing.

Done:

• [ ] In Software/so101/src/ui/lobby-panel.js, a pure exported helper decides which dialog actions show: Delete for owner and moderators; Mute and Ban for the owner on anyone else's line, and for a verified moderator on a line that is not their own, not the owner's and not another moderator's (the dialog needs the author's role on the line; use what the chat message already carries, or add it in the lobby's chat frame if missing).
• [ ] Tests in src/ui/lobby-panel.test.ts of that helper: owner sees all three, a moderator sees Mute and Ban on a plain user's line but not on the owner's or another moderator's, and nobody sees them on their own line.
• [ ] bun x tsc --noEmit and bun --cwd Software/so101 test pass, including the first-visit gzip budget.