Refactor SAML configuration deployment and enhance Authentik integration

- Removed SAML configuration deployment calls from PostInstanceInitService.
- Updated DeploySamlConfigurationAsync to improve template fetching logic from Git and local directories.
- Added Authentik flow and keypair models for better representation in the UI.
- Enhanced SettingsViewModel to include Authentik settings with save and test functionality.
- Updated UI to support Authentik configuration, including dropdowns for flows and keypairs.
- Changed default CMS server name template to "app.ots-signs.com" across various files.
- Improved password handling in SshDockerCliService for secure shell command execution.
- Added new template file for settings-custom.php in the project structure.

OTSSignsOrchestrator.Core/Services/IAuthentikService.cs

@@ -13,12 +13,33 @@ public interface IAuthentikService
     /// then fetches the IdP metadata (entity ID, x509 cert, SSO/SLO URLs).
     /// If the application already exists (by slug), returns its existing metadata.
     /// </summary>
-    /// <param name="instanceAbbrev">Short customer abbreviation (used in naming).</param>
-    /// <param name="instanceBaseUrl">Full base URL of the Xibo instance (e.g. https://app.ots-signs.com/demo).</param>
-    /// <param name="ct">Cancellation token.</param>
-    /// <returns>IdP metadata needed for the SAML PHP configuration.</returns>
     Task<AuthentikSamlConfig> ProvisionSamlAsync(
         string instanceAbbrev,
         string instanceBaseUrl,
         CancellationToken ct = default);
+
+    /// <summary>
+    /// Tests the connection to Authentik by fetching the current user.
+    /// Optionally accepts override URL/key for testing before saving.
+    /// </summary>
+    Task<(bool Success, string Message)> TestConnectionAsync(
+        string? overrideUrl = null,
+        string? overrideApiKey = null,
+        CancellationToken ct = default);
+
+    /// <summary>
+    /// Returns all available flows from Authentik.
+    /// </summary>
+    Task<List<AuthentikFlowItem>> ListFlowsAsync(
+        string? overrideUrl = null,
+        string? overrideApiKey = null,
+        CancellationToken ct = default);
+
+    /// <summary>
+    /// Returns all certificate keypairs from Authentik.
+    /// </summary>
+    Task<List<AuthentikKeypairItem>> ListKeypairsAsync(
+        string? overrideUrl = null,
+        string? overrideApiKey = null,
+        CancellationToken ct = default);
 }