Bug fix for domain names with empty string instead of null. Form errors and some security fixes

db/migrate/20251109011443_fix_empty_domain_patterns.rb

@@ -0,0 +1,17 @@
+class FixEmptyDomainPatterns < ActiveRecord::Migration[8.1]
+  def up
+    # Convert empty string domain_patterns to NULL
+    # This fixes a unique constraint issue where multiple OIDC apps
+    # had empty string domain_patterns, causing uniqueness violations
+    execute <<-SQL
+      UPDATE applications
+      SET domain_pattern = NULL
+      WHERE domain_pattern = ''
+    SQL
+  end
+
+  def down
+    # No need to reverse this - empty strings and NULL are functionally equivalent
+    # for OIDC applications where domain_pattern is not used
+  end
+end