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/Cargo.toml

@@ -21,7 +21,7 @@ zip.workspace = true
 tracing.workspace = true
 chrono.workspace = true
 rand.workspace = true
-axum = { version = "0.8", features = ["multipart", "macros"] }
+axum = { version = "0.8", features = ["multipart", "macros", "ws"] }
 tower = { version = "0.5", features = ["util"] }
 tower-http = { version = "0.6", features = ["fs", "trace", "compression-gzip", "set-header"] }
 tracing-subscriber = { version = "0.3", features = ["env-filter", "fmt"] }