feat: Implement API client and token models with hashing and JWT authentication

- Added ApiClientModel and ApiTokenModel for managing API clients and tokens.
- Introduced ConfigurationDefinitionModel and ConfigurationValueModel for configuration management.
- Created CredentialSecretModel for storing credential secrets.
- Developed DeploymentArtifactModel and DeploymentBatchModel for deployment management.
- Enhanced DeploymentTargetModel and DeploymentTemplateSelectionModel to support template revisions.
- Added TemplateRevisionModel and TemplateVersionModel for versioning templates.
- Implemented ApiClientSecretHasher for secure secret hashing.
- Created ApiTokenService for generating and validating JWT tokens.
- Updated QueueJobService to handle deployment requests with artifacts.
- Configured authentication settings in appsettings.json for JWT and Negotiate authentication.

Services/ApiClientSecretHasher.cs

@@ -0,0 +1,58 @@
+using System.Security.Cryptography;
+
+namespace Microsoft.SelfService.Portal.Core.API.Services
+{
+    public static class ApiClientSecretHasher
+    {
+        private const int SaltSize = 16;
+        private const int KeySize = 32;
+        private const int DefaultIterations = 100_000;
+
+        public static string HashSecret(string secret)
+        {
+            var salt = RandomNumberGenerator.GetBytes(SaltSize);
+            var hash = Rfc2898DeriveBytes.Pbkdf2(secret, salt, DefaultIterations, HashAlgorithmName.SHA256, KeySize);
+
+            return string.Join(
+                '.',
+                "PBKDF2-SHA256",
+                DefaultIterations.ToString(),
+                Convert.ToBase64String(salt),
+                Convert.ToBase64String(hash));
+        }
+
+        public static bool VerifySecret(string secret, string storedHash)
+        {
+            var parts = storedHash.Split('.');
+            if (parts.Length != 4 || parts[0] != "PBKDF2-SHA256")
+            {
+                return false;
+            }
+
+            if (!int.TryParse(parts[1], out var iterations))
+            {
+                return false;
+            }
+
+            var salt = Convert.FromBase64String(parts[2]);
+            var expectedHash = Convert.FromBase64String(parts[3]);
+            var actualHash = Rfc2898DeriveBytes.Pbkdf2(secret, salt, iterations, HashAlgorithmName.SHA256, expectedHash.Length);
+
+            return CryptographicOperations.FixedTimeEquals(actualHash, expectedHash);
+        }
+
+        internal static string HashSecretForDemoData(string secret, string saltText)
+        {
+            var salt = System.Text.Encoding.UTF8.GetBytes(saltText);
+            Array.Resize(ref salt, SaltSize);
+            var hash = Rfc2898DeriveBytes.Pbkdf2(secret, salt, DefaultIterations, HashAlgorithmName.SHA256, KeySize);
+
+            return string.Join(
+                '.',
+                "PBKDF2-SHA256",
+                DefaultIterations.ToString(),
+                Convert.ToBase64String(salt),
+                Convert.ToBase64String(hash));
+        }
+    }
+}