✨➕ vanth, workspace: Add entity ID system and serialization dependencies

- Added new modules `entity` and `store` to `vanth` crate for ECS foundations
- Implemented generic `Id` type with serialization/deserialization support
- Introduced `serde` and `serde_json` dependencies in workspace and vanth crate
- Defined `Vanth` struct and `ContentHash` component in `lib.rs`
- Added placeholder `Store` component in new module
- Updated workspace configuration with `resolver = "3"` and dependency versions

Cargo.lock

@@ -456,6 +456,12 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "itoa"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
+
 [[package]]
 name = "js-sys"
 version = "0.3.77"
@@ -607,6 +613,12 @@ version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a0d197bd2c9dc6e53b84da9556a69ba4cdfab8619eb41a8bd1cc2027a0f6b1d"
 
+[[package]]
+name = "ryu"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
@@ -633,6 +645,18 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_json"
+version = "1.0.141"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30b9eff21ebe718216c6ec64e1d9ac57087aad11efc64e32002bce4a0d4c03d3"
+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.10"
@@ -762,6 +786,8 @@ version = "0.1.0"
 dependencies = [
  "bevy_app",
  "bevy_ecs",
+ "serde",
+ "serde_json",
 ]
 
 [[package]]