Reconciliation Bond

POLICY + STUB ONLY — refundable-bond / slash-on-mismatch policy.

RES-017 §L3 pairs the audit lottery with a refundable bond an agent owner posts when opting into reconciliation: post a bond at grant time, get it back in full if every audited reconciliation comes back "consistent", have it partially slashed if an audit comes back "delta_flagged" (the economic backstop behind the probabilistic-audit argument in select_audit_candidates — a bond makes cheating negative-expected-value even for a builder willing to gamble on not being sampled).

This endpoint is a STUB: it never creates a Stripe object and never moves money (BLOCKED on the founder — escrow/bond product + payments infra is a separate, founder-approved workstream). It always returns 503 (never 501): app/observability/sentry.py's before_send filter only special-cases 503 against its _INTENTIONAL_503_PHRASES allowlist, so a 501 here would page Sentry on every single call to a permanently-unbuilt feature. 404s (via require_bpp_reconciliation_enabled) unless BOTH BPP_ENABLED and BPP_RECONCILIATION_ENABLED are true.