Initial commit: split VNOX monorepo into VNOX-Server

Unified server binary (vnox-serverd) combining:
- Gateway (TCP, auth, channels, sessions, SQLite)
- Voice-node (UDP relay, Opus, jitter buffer)

Standalone gateway (vnox-gateway) and voice-node (vnox-voice-node) preserved as sub-crates.

serverd/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name        = "vnox-serverd"
+description = "VNOX unified server — gateway TCP + voice UDP in one binary"
+version.workspace    = true
+edition.workspace    = true
+license.workspace    = true
+authors.workspace    = true
+repository.workspace = true
+
+[[bin]]
+name = "vnox-serverd"
+path = "src/main.rs"
+
+[dependencies]
+vnox-gateway    = { path = "../gateway" }
+vnox-voice-node = { path = "../voice-node" }
+
+tokio.workspace              = true
+tracing.workspace            = true
+tracing-subscriber.workspace = true
+anyhow.workspace             = true
+toml.workspace               = true
+serde.workspace              = true