wasm: add experimental argon2i checker

Signed-off-by: Xe Iaso <me@xeiaso.net>

wasm/anubis/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "anubis"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

wasm/anubis/src/lib.rs

@@ -0,0 +1,25 @@
+#[cfg(target_arch = "wasm32")]
+mod hostimport {
+    #[link(wasm_import_module = "anubis")]
+    unsafe extern "C" {
+        /// The runtime expects this function to be defined. It is called whenever the Anubis check
+        /// worker processes about 1024 hashes. This can be a no-op if you want.
+        fn anubis_update_nonce(nonce: u32);
+    }
+
+    /// Safe wrapper to `anubis_update_nonce`.
+    pub fn update_nonce(nonce: u32) {
+        unsafe {
+            anubis_update_nonce(nonce);
+        }
+    }
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+mod hostimport {
+    pub fn update_nonce(_nonce: u32) {
+        // This is intentionally blank
+    }
+}
+
+pub use hostimport::update_nonce;