✨🧪♻️➕ vanth, vanth_derive: Add derive macro for Vanth trait implementation

- Added `vanth_derive` crate with a procedural macro to automatically implement the `Vanth` trait for structs, including generics.
- Refactored `vanth` crate by removing obsolete `vanth.rs` file.
- Implemented `PartialEq` for `Ty` to enable comparisons with string values and another `Ty`.
- Added integration tests for deriving `Vanth` with generic parameters.
- Updated dependencies: added `quote`, `syn`, and `proc-macro2` crates.

crates/vanth_derive/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "vanth_derive"
+version.workspace = true
+edition.workspace = true
+
+[lib]
+proc-macro = true
+
+[dependencies]
+quote.workspace = true
+syn.workspace = true
+proc-macro2.workspace = true

crates/vanth_derive/src/lib.rs

@@ -0,0 +1,51 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, DeriveInput, GenericParam, Generics};
+use syn::parse_quote;
+
+#[proc_macro_derive(Vanth)]
+pub fn vanth_derive(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+
+    let name = input.ident.clone();
+
+    let mut generics = input.generics.clone();
+
+    let type_params: Vec<syn::Ident> = generics.params.iter().filter_map(|param| {
+        if let GenericParam::Type(type_param) = param {
+            Some(type_param.ident.clone())
+        } else {
+            None
+        }
+    }).collect();
+
+    let mut where_clause = generics.where_clause.clone().unwrap_or_else(|| parse_quote!(where ));
+    for tp in &type_params {
+        where_clause.predicates.push(parse_quote!(#tp : vanth::Vanth));
+    }
+
+    let (impl_generics, ty_generics, _) = generics.split_for_impl();
+
+    let generics_code = if type_params.is_empty() {
+        quote! { String::new() }
+    } else {
+        quote! {
+            format!("<{}>", [#(#type_params::ty().path.join("::")),*].join(","))
+        }
+    };
+
+    let expanded = quote! {
+        impl #impl_generics vanth::Vanth for #name #ty_generics #where_clause {
+            fn ty() -> vanth::Ty {
+                let module_path = module_path!();
+                let mut path: Vec<String> = module_path.split("::").map(|s| s.to_string()).collect();
+                let base_name = stringify!(#name);
+                let generics_str = #generics_code;
+                path.push(format!("{}{}", base_name, generics_str));
+                vanth::Ty { path }
+            }
+        }
+    };
+
+    TokenStream::from(expanded)
+}