fix: enable email sign-in method alongside username in all modes

The sign-in experience must always include both email+password and
username+password methods. The admin user signs in with their email
(admin@company.com) which the sign-in UI detects as email type.
With only username method enabled, Logto rejects it with "this
sign-in method is not activated."

Fixes both bootstrap Phase 8c and EmailConnectorService disable path.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/main/java/net/siegeln/cameleer/saas/vendor/EmailConnectorService.java

@@ -138,6 +138,7 @@ public class EmailConnectorService {
                 ),
                 "signIn", Map.of(
                     "methods", List.of(
+                        Map.of("identifier", "email", "password", true, "verificationCode", false, "isPasswordPrimary", true),
                         Map.of("identifier", "username", "password", true, "verificationCode", false, "isPasswordPrimary", true)
                     )
                 )