add xmldoc comments

web/backend/Infrastructure/Infrastructure.PasswordHashing/IPasswordInfrastructure.cs

@@ -1,7 +1,22 @@
 namespace Infrastructure.PasswordHashing;
 
+/// <summary>
+/// Service for hashing and verifying user passwords.
+/// </summary>
 public interface IPasswordInfrastructure
 {
+    /// <summary>
+    /// Hashes a plaintext password, generating a new random salt.
+    /// </summary>
+    /// <param name="password">The plaintext password to hash.</param>
+    /// <returns>A string encoding both the salt and the resulting hash, suitable for storage.</returns>
     public string Hash(string password);
+
+    /// <summary>
+    /// Verifies a plaintext password against a previously stored hash.
+    /// </summary>
+    /// <param name="password">The plaintext password to verify.</param>
+    /// <param name="stored">The stored salt/hash string previously produced by <see cref="Hash"/>.</param>
+    /// <returns><c>true</c> if the password matches the stored hash; otherwise <c>false</c>.</returns>
     public bool Verify(string password, string stored);
 }