fix: fix unicode in roles, add password confirmation field

- RolesTab: wrap \u00b7 in JS expression {'\u00b7'} so JSX renders the middle dot correctly instead of literal backslash-u sequence
- UsersTab: add confirm password field with mismatch validation, hint text for password policy, and reset on cancel/success
- UserManagement.module.css: add .hintText style for password policy hint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/src/pages/Admin/RolesTab.tsx

@@ -179,7 +179,7 @@ export default function RolesTab({ highlightId, onHighlightConsumed }: { highlig
                       )}
                     </div>
                     <div className={styles.entityMeta}>
-                      {role.description || '\u2014'} \u00b7{' '}
+                      {role.description || '\u2014'} {'\u00b7'}{' '}
                       {getAssignmentCount(role)} assignments
                     </div>
                     <div className={styles.entityTags}>