chore: update demo to show Argon2

Author: surajkumar

demo/src/commonMain/kotlin/com/wannaverse/crypto/App.kt

@@ -10,6 +10,9 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import com.wannaverse.crypto.core.Encoding.fromHex
 import com.wannaverse.crypto.core.Encoding.toHex
+import com.wannaverse.crypto.hashing.Argon2
+import com.wannaverse.crypto.hashing.Argon2Config
+import com.wannaverse.crypto.hashing.Argon2Type
 import com.wannaverse.crypto.hashing.sha1
 import org.jetbrains.compose.ui.tooling.preview.Preview
 
@@ -30,10 +33,25 @@ fun App() {
             val fromHex = fromHex(toHex)
             val isEqual = hashed.contentEquals(fromHex)
 
-            Text("" + hashed)
-            Text("" + toHex)
-            Text("" + fromHex)
-            Text("" + isEqual)
+            Text("SHA1: $toHex")
+            Text("Hex roundtrip: $isEqual")
+
+            // Argon2 password hashing example
+            val password = "mypassword".encodeToByteArray()
+            val salt = "somesalt12345678".encodeToByteArray()
+            val argon2 = Argon2()
+            val argon2Hash = argon2.hash(
+                password = password,
+                salt = salt,
+                config = Argon2Config(
+                    type = Argon2Type.Argon2id,
+                    hashLength = 16,
+                    parallelism = 1,
+                    memorySizeKB = 16,
+                    iterations = 3,
+                )
+            )
+            Text("Argon2id: ${toHex(argon2Hash)}")
 
         }
     }