SEC-028 -- a rotated-out server signing key must stop being trusted even when the agent cannot phone home. pubkey.go: bounded stale-cache window on public-key fetch failure; past the window (or when cache age is unknown) it fails closed instead of trusting the cached key indefinitely. Window length is operator policy (command_signing.stale_key_max_age_hours, default 168h/7d) delivered fleet-wide via GET /agents/:id/config; the [1h, 30d] clamp and the existence of the ceiling are doctrine, not knobs. verification.go: CheckKeyRotation refuses when the named key_id is not in the server active set (no primary fallback), and applies the same bounded-stale ceiling to the active-set fetch-failure path so key_id'd commands are no weaker than keyless ones. Server carries the default + 1-720h validation; web surfaces it in Security Settings.
SEC-029 -- the standalone OSV.dev client retries transient transport/5xx/429 with exponential backoff and trips a process-wide circuit breaker after a run of failures, fast-failing to 'unreachable'. Verdict semantics unchanged and still fail-closed; the resilience only stops a transient scanner blip from forcing an operator override.
GATE-004 #4 -- Consumer.ProcessToken holds a mutex so the replay-state guards are never raced by a concurrent caller. Today's single caller (the poll loop) never overlaps; this enforces the one-token-at-a-time invariant for future callers (local-API trigger, retry worker).
RAF/verification/03 and RAF/security/05 document the key-path and OSV changes. ETHOS #3, #4; forward-only doctrine.
0b1b8124b0