add tracing feature to jacquard-axum

crates/jacquard-axum/Cargo.toml

···
 [features]
 default = ["service-auth"]
 service-auth = ["jacquard-common/service-auth", "dep:jacquard-identity", "dep:multibase"]
+tracing = []
 
 [dev-dependencies]
 axum-macros = "0.5.0"

crates/jacquard-axum/src/service_auth.rs

···
 
     match codec {
         // p256-pub (0x1200)
-        [0x80, 0x24] => PublicKey::from_p256_bytes(key_material).ok(),
+        [0x80, 0x24] => PublicKey::from_p256_bytes(key_material)
+            .inspect_err(|_e| {
+                #[cfg(feature = "tracing")]
+                tracing::error!("Failed to parse p256 public key: {}", _e);
+            })
+            .ok(),
         // secp256k1-pub (0xe7)
-        [0xe7, 0x01] => PublicKey::from_k256_bytes(key_material).ok(),
-        _ => None,
+        [0xe7, 0x01] => PublicKey::from_k256_bytes(key_material)
+            .inspect_err(|_e| {
+                #[cfg(feature = "tracing")]
+                tracing::error!("Failed to parse secp256k1 public key: {}", _e);
+            })
+            .ok(),
+        _ => {
+            #[cfg(feature = "tracing")]
+            tracing::error!("Unsupported public key multicodec: {:?}", codec);
+            None
+        }
     }
 }