✨♻️ bevy_vanth, vanth, vanth_derive, flake: Add Bevy integration crate and refactor entity/networking

- Created new crate `bevy_vanth` with basic plugin structure for Bevy integration.
- Refactored `Id` generation in `vanth` to use `OsRng` and removed redundant `to_u128_pair`/`from_u128_pair` methods.
- Moved networking functionality into new `net` module with `Node`, `Packet`, and `Message` types.
- Updated `vanth_derive` to use `proc-macro-crate` for reliable crate path resolution.
- Added `rand` dependency to replace custom ID generation logic.
- Updated `Cargo.toml`/`Cargo.lock` with new dependencies: `bevy_app`, `nix`, `cfg_aliases`, `proc-macro-crate`.
- Modified `README.md` with improved project description.
- Added commented clippy check in `flake.nix`.

Cargo.toml

@@ -12,6 +12,7 @@ name = "vanth"
 [workspace.dependencies]
 clap = { version = "4.5.42", features = ["derive"] }
 bevy_ecs = "0.16.1"
+bevy_app = "0.16.1"
 bincode = "2.0.1"
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.140"
@@ -22,8 +23,10 @@ syn = { version = "2.0", features = ["full"] }
 proc-macro2 = "1.0"
 rusqlite = { version = "0.32.1", features = ["bundled"] }
 tempfile = "3.12.0"
-rand_core = "0.6.4"
-rand_chacha = { version = "0.3.1", features = ["serde1"] }
+rand = "0.9.2"
+rand_chacha = { version = "0.9.0", features = ["serde"] }
+rand_core = "0.9.0"
 tracing = "0.1.41"
 tracing-subscriber = "0.3.19"
 assert_cmd = "2.0.17"
+proc-macro-crate = "3.3.0"