Add central live map backend: chunk/player ingest, Vantage sidecar supervisor and proxy

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DjMbLQujBHunCCu5GpsHaT

panel/server/src/main.rs

@@ -22,6 +22,7 @@ async fn main() -> anyhow::Result<()> {
     let bind = cfg.bind.clone();
     let state = build_state(cfg, pool).await?;
     bootstrap_admin(&state).await?;
+    state.livemap.spawn_reaper();
 
     let listener = tokio::net::TcpListener::bind(&bind).await?;
     tracing::info!("SCOPENET panel v{} listening on http://{bind}", env!("CARGO_PKG_VERSION"));