Adds two @WebMvcTest assertions verifying that POST /api/users/me/password
and POST /api/users/{id}/force-logout without an XSRF-TOKEN header return
403 with code CSRF_TOKEN_MISSING.
Addresses Nora Concern 9 from PR #617 review.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>