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.

Cargo.toml

@@ -0,0 +1,35 @@
+[workspace]
+resolver = "2"
+members = [
+    "gateway",
+    "voice-node",
+    "serverd",
+]
+
+[workspace.package]
+version      = "0.1.0"
+edition      = "2024"
+license      = "GPL-3.0"
+authors      = ["VNOX Contributors"]
+repository   = "https://github.com/loki5512344/Vnox"
+rust-version = "1.85"
+
+[workspace.dependencies]
+tokio = { version = "1.52", features = ["full"] }
+serde      = { version = "1", features = ["derive"] }
+serde_json = "1"
+ed25519-dalek    = { version = "2", features = ["rand_core"] }
+x25519-dalek     = { version = "2", features = ["static_secrets"] }
+chacha20poly1305 = "0.10"
+argon2           = "0.5"
+rand             = "0.8"
+opus = "0.3"
+uuid = { version = "1", features = ["v4"] }
+hex = "0.4"
+hkdf = "0.13"
+sha2 = "0.11"
+tracing            = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+anyhow    = "1"
+thiserror = "2"
+toml = "1.1"