Four polish improvements aimed at production-floor usability.
1. Empty-state placeholder for the participants card. When Participants.Count == 0, the DataGrid is hidden in favor of a friendly 'Waiting for Teams' panel: faded dragon mark, headline, explainer, and a four-item checklist (Teams running? NDI broadcast on? Discovery group correct? Firewall clear?). New CountToVisibilityConverter (with optional 'empty' parameter to invert) drives both the placeholder and the DataGrid visibility from the same Participants.Count source.
2. Per-pipeline error / no-signal surfacing. IsoHealthStats grows an init-only State property populated from IsoPipeline.State. ParticipantViewModel.UpdateStats maps that to a StateLabel ('LIVE' / 'NO SIGNAL' / 'ERROR' / 'STARTING' / '—'). The ISO toggle button gains DataTriggers on StateLabel — coral-tinted '● ERROR' when the supervisor gives up, amber-tinted '● NO SIGNAL' when the slate threshold trips. Operators can see at a glance which pipelines are broken.
3. JetBrains Mono Variable v2.304 (OFL) bundled at Assets/Fonts/JetBrainsMono.ttf. Wd.Font.Mono now points at the embedded font so machine names, timecodes, and stat counters render in JetBrains Mono regardless of system fonts. Falls back to Cascadia Mono / Consolas if the resource is missing.
4. Tooltip pass over every interactive control in the settings panel (framerate / resolution / aspect / audio / discovery group / output group / hide-local checkbox / Apply button / per-row Output Name textbox / per-row ISO toggle). Operators learn affordances on hover instead of by trial and error.
Tests: 76/76 unit + 9/9 NDI integration green.
Replaces the Stone theme with Wild Dragon branding (canvas #0A0A0A, accent cyan #97EDF0, secondary #9AE0FD, coral alert #FB819C — sourced from wilddragon.net) and reorganizes MainWindow into a Microsoft Teams-style three-column layout: a 72px left rail (logo + Participants/Settings nav + engine-status indicator), a center content area (header + participants card), and a right settings panel.
Adds InitialsConverter so participant avatars render real initials (Brendon Power -> 'BP', '(Local)' -> 'L') instead of a generic glyph. Drops the obsolete StoneTheme.xaml; the project now ships exactly one theme dictionary.
Typography: Inter (with Segoe UI Variable Display fallback) for the sans stack, JetBrains Mono (Cascadia Mono fallback) for machine names and timecodes — matching the wilddragon.net site.
Verified live against the running Teams meeting: app launches, participant 'Brendon Power' displays with avatar, settings panel surfaces NDI groups + Hide-Local toggle, engine status pill shows green/live.
