fix(security): prevent NPE in DSUserDetails.getClaims()

Add null check for oidcUserInfo before calling getClaims() to prevent
NullPointerException when DSUserDetails is constructed without OIDC info.

Returns empty map instead of throwing NPE when OIDC info is not available.

Author: devondragon

src/main/java/com/digitalsanctuary/spring/user/service/DSUserDetails.java

@@ -199,7 +199,7 @@ public String getName() {
 
 	@Override
 	public Map<String, Object> getClaims() {
-		return oidcUserInfo.getClaims();
+		return oidcUserInfo != null ? oidcUserInfo.getClaims() : Map.of();
 	}
 
 	@Override