Fix SEC-01: require password for TOTP enroll

- REST handleTOTPEnroll now requires password field in request body
- gRPC EnrollTOTP updated with password field in proto message
- Both handlers check lockout status and record failures on bad password
- Updated Go, Python, and Rust client libraries to pass password
- Updated OpenAPI specs with new requestBody schema
- Added TestTOTPEnrollRequiresPassword with no-password, wrong-password,
  and correct-password sub-tests

Security: TOTP enrollment now requires the current password to prevent
session-theft escalation to persistent account takeover. Lockout and
failure recording use the same Argon2id constant-time path as login.

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

clients/python/tests/test_client.py

@@ -191,7 +191,7 @@ def test_enroll_totp(admin_client: Client) -> None:
             json={"secret": "JBSWY3DPEHPK3PXP", "otpauth_uri": "otpauth://totp/MCIAS:alice?secret=JBSWY3DPEHPK3PXP&issuer=MCIAS"},
         )
     )
-    secret, uri = admin_client.enroll_totp()
+    secret, uri = admin_client.enroll_totp("testpass123")
     assert secret == "JBSWY3DPEHPK3PXP"
     assert "otpauth://totp/" in uri
 @respx.mock