Agent heartbeats now carry an applied-topology snapshot. The master
heartbeat handler compares the reported version_hash against what
canonical_hash yields for the hydrated topology pinned to that host
and flags Topology.needs_resync on divergence (or when the agent
reports no topology at all while master expects one).
The mutator watch loop gains reconcile_agent_resyncs, which re-pushes
the current hydrated blob via AgentClient.apply_topology without
touching status, then clears the flag on success. Push failures leave
the flag set so the next tick retries.
Schemathesis was failing CI on routes that returned status codes not
declared in their OpenAPI responses= dicts. Adds the missing codes
across swarm_updates, swarm_mgmt, swarm, fleet and attackers routers.
Also adds 400 to every POST/PUT/PATCH that accepts a JSON body —
Starlette returns 400 on malformed/non-UTF8 bodies before FastAPI's
422 validation runs, which schemathesis fuzzing trips every time.
No handler logic changed.
New POST /swarm/heartbeat on the swarm controller. Workers post every
~30s with the output of executor.status(); the master bumps
SwarmHost.last_heartbeat and re-upserts each DeckyShard with a fresh
DeckyConfig snapshot and runtime-derived state (running/degraded).
Security: CA-signed mTLS alone is not sufficient — a decommissioned
worker's still-valid cert could resurrect ghost shards. The endpoint
extracts the presented peer cert (primary: scope["extensions"]["tls"],
fallback: transport.get_extra_info("ssl_object")) and SHA-256-pins it
to the SwarmHost.client_cert_fingerprint stored for the claimed
host_uuid. Extraction is factored into _extract_peer_fingerprint so
tests can exercise both uvicorn scope shapes and the both-unavailable
fail-closed path without mocking uvicorn's TLS pipeline.
Adds get_swarm_host_by_fingerprint to the repo interface (SQLModel
impl reuses the indexed client_cert_fingerprint column).
