Voice: status icons + live speaking indicator

[hardlygospel]

What

The voice roster used to show each participant as @name <word> with the status as plain text, and the controls line was text-only. This adds status icons and a live speaking indicator:

• Each participant row gets a status icon: 🟢 speaking · ⚪ listening · 🔇 muted · 🔕 deafened.
• A speaking user's name pops green + bold while they're talking — a real-time "who's talking" cue.
• The controls line gains matching icons: 🟢 live · ⏎ leave · 🎤 u mic · 🎧 d deafen.

How

Presence is factored into a small priority-ordered enum (deafened > muted > speaking > listening) with icon() / label() / color(), so the roster and the controls line stay in sync and the logic is unit-testable.

Tests

Two new unit tests cover the presence precedence and that every state has a distinct icon and label. cargo test -p late-ssh --lib voice is green; no new clippy warnings.

UI-only change, contained to voice/ui.rs. No service, schema, or config changes.

Thanks 🙏

• mat (@mpiorowski) — for late.sh and the voice feature this builds on. Thank you for the foundation that makes polish like this possible.