v2.0.0-rc.1

This is a pre-release for testing against full SimpleSAMLphp pre-production
environments; expect breaking changes relative to v1.0.7 (minimum PHP is now
8.3, minimum SimpleSAMLphp is now 2.5.2, and handleLoginPass() was renamed).

Added

• The sources option is now wired through to the login page: the controller
  passes a sources list (id, label, userpass) to the template, which
  renders one form per source. authsource values not in sources are
  rejected.
• Tests for the Multiauthsinglepage authentication source (constructor
  validation, credential guard, session handling, logout error path).

Changed

• Require PHP >= 8.3 and SimpleSAMLphp >= 2.5.2.
• Multiauthsinglepage::authenticate() now returns never, to match
  saml:SP in SimpleSAMLphp 2.5.
• Any core:UserPassBase source (e.g. sqlauth:SQL, core:AdminPassword)
  is now authenticated on the single page, not just ldap:Ldap. The
  dispatch checks instanceof UserPassBase; handleLoginPass() was renamed
  to handleUserPassLogin() and typed accordingly.
• handleUserPassLogin() uses LdapSinglePage::loginSinglePage() when
  available and only falls back to reflection otherwise.
• Replaced the deprecated Request::get() (Symfony 7.4) with explicit
  query-string / POST-body reads.
• Single code style tool (phpcs with the SimpleSAMLphp standard); dropped
  php-cs-fixer.
• Loosened the simplesamlphp-module-ldap constraint from 2.5.2 to
  ^2.5.2.
• The test bootstrap defines SIMPLESAMLPHP_TEST_NOEXIT so redirect flows
  can be exercised in tests.
• Rewrote the README with a real configuration example.

Fixed

• The login template read errorTitle / errorDesc, which the controller
  never set, so errors were never shown; it now uses errorcode /
  errorcodes / errorparams.
• handleUserPassLogin() (née handleLoginPass()) no longer raises a
  TypeError when the username or password is missing; it throws
  Error\Error(WRONGUSERPASS) instead.
• The full authentication state is no longer written to the debug log.
• LICENSE was an empty file; it now contains the GNU LGPL 2.1 text.
• Moved the SuccessAuthSource test fixture out of src/ into tests/,
  fixing its PSR-4 mapping.