- Add SamlEidMsg enum combining messages from both EidasMsg and BankIDMsg
- Add create_authn_info() function for initiating SAML authentication
- Add samleid session namespace property to EduidSession for session management

Add SamlEidNamespace to session namespaces and SamlEidAcsAction to
acs_enums. Add BankIDMethodTests with all 26 test methods ported from
bankid/tests/test_app.py, using SamlEidMsg and samleid response types.

…erage for error paths

- Remove duplicate shadowed methods in BankIDMethodTests (Python MRO made them dead code)
- Unskip 5 backdoor tests that work with default method='freja'
- Add test_verify_credential_eidas_not_allowed (views.py:87-89)
- Add test_saml2_metadata endpoint test (views.py:358-361)
- Add test_nin_verify_loa_mismatch for wrong LOA (acs_actions.py:35-38)
- Add test_unsolicited_saml_response for unknown request ID (views.py:290-295)

Test suite: 43 passed, 0 failed, 0 skipped

- Add tests for views.py error paths: invalid frontend_action, missing
  credential, method not available, magic cookie branches, get-status
- Add unit tests for helpers.py ValueError and proofing.py UnsupportedMethod
- Add verify-credential identity not matching test
- Fix test_nin_staging_remap_verify_bankid -> test_webauthn_token_verify_backdoor
- Remove duplicate @patch decorator and duplicate mock assignment

Test suite: 54 passed, 0 failed, 0 skipped
Coverage: 90% -> 93%

Run 25 tests with both freja and bankid methods using MethodConfig and
subTest loops, increasing coverage. Three backdoor tests remain
freja-only since ProofingMethodBankID does not implement magic cookie
NIN override.

use ruff disable/enable instead of ignoring rule per line