Gate blocked actions behind an in-place terms acceptance dialog

A member whose account has not accepted the terms in force now gets one
dialog on the action they attempted instead of a dead-end refusal. The
client handler is the single TermsGate, wired into every Http POST helper
so the four optimistic controllers cannot swallow the gate into an error
flash, and the original request is replayed once the acceptance is
recorded. Reading the site and deleting an account stay unblocked.

apple.md is the source brief the compliance research documents reference.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

devplacepy/routers/auth/terms.py

@@ -15,6 +15,8 @@ from devplacepy.utils import clear_user_cache, require_user
 logger = logging.getLogger(__name__)
 router = APIRouter()
 
+TERMS_ACCEPTANCE_CODE = "terms_acceptance_required"
+
 
 def current_terms_version() -> str:
     return get_setting("terms_version", "1") or "1"