Fix warnings: unused variable, profile in non-root package

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/crates/warzone-wasm/Cargo.toml

@@ -21,6 +21,4 @@ x25519-dalek.workspace = true
 ed25519-dalek.workspace = true
 uuid = { version = "1", features = ["v4", "serde", "js"] }
 
-[profile.release]
-opt-level = "s"
-lto = true
+# profile.release is set at workspace root

warzone/crates/warzone-wasm/src/lib.rs

@@ -226,7 +226,7 @@ pub fn self_test() -> Result<String, JsValue> {
             public_key: *bob_otpks[0].public.as_bytes(),
         }),
     };
-    let bob_bundle_bytes = bincode::serialize(&bob_bundle)
+    let _bob_bundle_bytes = bincode::serialize(&bob_bundle)
         .map_err(|e| JsValue::from_str(&e.to_string()))?;
 
     // Alice initiates X3DH and encrypts