hide login if login type disabled (#5438)

# Description of Changes

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- Why the change was made
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Closes #(issue_number)
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## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
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### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

app/proprietary/src/main/java/stirling/software/proprietary/controller/api/ProprietaryUIDataController.java

@@ -169,7 +169,10 @@ public class ProprietaryUIDataController {
 
         OAUTH2 oauth = securityProps.getOauth2();
 
-        if (oauth != null && oauth.getEnabled()) {
+        // Only add OAuth2 providers if loginMethod allows it
+        if (oauth != null
+                && oauth.getEnabled()
+                && securityProps.isOauth2Active()) { // This checks loginMethod
             if (oauth.isSettingsValid()) {
                 String firstChar = String.valueOf(oauth.getProvider().charAt(0));
                 String clientName =
@@ -201,6 +204,7 @@ public class ProprietaryUIDataController {
         }
 
         SAML2 saml2 = securityProps.getSaml2();
+        // Only add SAML2 providers if loginMethod allows it
         if (securityProps.isSaml2Active() && applicationProperties.getPremium().isEnabled()) {
             String samlIdp = saml2.getProvider();
             String saml2AuthenticationPath = "/saml2/authenticate/" + saml2.getRegistrationId();

app/proprietary/src/main/java/stirling/software/proprietary/security/controller/api/AuthController.java

@@ -21,6 +21,7 @@ import jakarta.servlet.http.HttpServletResponse;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
+import stirling.software.common.model.ApplicationProperties;
 import stirling.software.proprietary.audit.AuditEventType;
 import stirling.software.proprietary.audit.AuditLevel;
 import stirling.software.proprietary.audit.Audited;
@@ -44,6 +45,7 @@ public class AuthController {
     private final JwtServiceInterface jwtService;
     private final CustomUserDetailsService userDetailsService;
     private final LoginAttemptService loginAttemptService;
+    private final ApplicationProperties.Security securityProperties;
 
     /**
      * Login endpoint - replaces Supabase signInWithPassword
@@ -60,6 +62,17 @@ public class AuthController {
             HttpServletRequest httpRequest,
             HttpServletResponse response) {
         try {
+            // Check if username/password authentication is allowed
+            if (!securityProperties.isUserPass()) {
+                log.warn(
+                        "Username/password login attempted but not allowed by current login method configuration");
+                return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                        .body(
+                                Map.of(
+                                        "error",
+                                        "Username/password authentication is not enabled. Please use the configured authentication method."));
+            }
+
             // Validate input parameters
             if (request.getUsername() == null || request.getUsername().trim().isEmpty()) {
                 log.warn("Login attempt with null or empty username");