feat(auth): update request-code handler to be context-aware

Modifies the `/api/v1/auth/request-code` route handler to parse an
optional `is_dashboard_login` boolean field from the request body.

This flag is then passed to the `AuthService.initiateEmailSignIn`
method, enabling it to trigger the appropriate validation logic for
either a standard user-facing app sign-in or a restricted dashboard
login.

Author: fulleni

routes/api/v1/auth/request-code.dart

@@ -7,7 +7,11 @@ import 'package:ht_shared/ht_shared.dart'; // For exceptions
 /// Handles POST requests to `/api/v1/auth/request-code`.
 ///
 /// Initiates the email sign-in process by requesting a verification code
-/// be sent to the provided email address.
+/// be sent to the provided email address. It supports a context-aware flow
+/// for dashboard logins by checking for an `is_dashboard_login` flag in the
+/// request body. If this flag is true, the `AuthService` will perform
+/// additional checks to ensure the user exists and has the required
+/// permissions before sending a code.
 Future<Response> onRequest(RequestContext context) async {
   // Ensure this is a POST request
   if (context.request.method != HttpMethod.post) {
@@ -37,6 +41,9 @@ Future<Response> onRequest(RequestContext context) async {
     );
   }
 
+  // Check for the optional dashboard login flag. Default to false if not present.
+  final isDashboardLogin = (body['is_dashboard_login'] as bool?) ?? false;
+
   // Basic email format check (more robust validation can be added)
   // Using a slightly more common regex pattern
   final emailRegex = RegExp(
@@ -48,8 +55,11 @@ Future<Response> onRequest(RequestContext context) async {
   }
 
   try {
-    // Call the AuthService to handle the logic
-    await authService.initiateEmailSignIn(email);
+    // Call the AuthService to handle the logic, passing the context flag.
+    await authService.initiateEmailSignIn(
+      email,
+      isDashboardLogin: isDashboardLogin,
+    );
 
     // Return 202 Accepted: The request is accepted for processing,
     // but the processing (email sending) hasn't necessarily completed.