Add new dependencies and implement TUN interface initialization

- Updated Cargo.toml to include `etherparse` and enable async feature for `tun-rs`.
- Added `ip_match_network` function in network module for IP matching.
- Implemented TUN interface initialization in `tun.rs`.
- Enhanced client handling in `client.rs` to support new features and improved message handling.
- Refactored router messages to use a structured `VpnPacket`.
- Updated settings for spell checking in VSCode.

Cargo.toml

@@ -22,5 +22,6 @@ anyhow = "1.0.102"
 uuid = { version = "1.21.0", features = ["v4", "serde"] }
 ipnet = { version = "2.11.0", features = ["serde"] }
 base64 = "0.22.1"
-tun-rs = "2.8.2"
+tun-rs = { version = "2.8.2", features = ["async"] }
 chrono = "0.4.44"
+etherparse = "0.19.0"