SIENTIAPDE-1973: Implement per-connector OPC client certificates and remove legacy read engine.
This update overhauls certificate management, transitioning from a single platform certificate to individual client certificates defined in the slot configuration. The CertProvider now downloads certificates from MinIO based on certificate_id, applying dynamic security policies (mode, policy) from the slot. The legacy READ_ENGINE=legacy option and OpcManager have been entirely removed, standardizing on the ServerReader with strict slot v2 enforcement. Write command resolution (ServerConfigResolver) now consistently uses connectors joined with opc_certificates. The CERT_BUCKET environment variable is no longer used.
- GW1: write commands (C2) carry only the server_id; ServerConfigResolver
resolves the connection (command override, live pooled connection,
connectors, opc-servers) with a 60 s cache and a 10 s negative cache.
- GW2: write_status keeps the worst outcome (ok < error < session_bad,
pending/NULL replaced), same rule as the Laborious, built with SQLAlchemy
Core (no SQL formatting).
- GW3: update_write_status never raises; outcome (updated, kept,
row_not_found, invalid, error) logged and counted
(opc_write_status_update_total); runs off the event loop.
- GW4: the reason of a failed write is logged; opc_write_status_by_model
shows the last outcome; a bad timestamp is a failed write, not an
exception.
- GW5: the NATS first connect gives up after 5 s (nats-py's defaults block
the main loop for about 4 minutes while NATS is down); reconnection after
it is unbounded; idle_sweep restarts a connection closed for good; stop()
is safe on a closed connection.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
main's requirements.txt unpins asyncua (PR #30), so CI installs 2.0.1,
where DataValue's field was renamed StatusCode_ -> StatusCode. The old
kwarg made every OPC write raise TypeError at runtime - masked locally
by a stale asyncua 1.0.6 in the dev conda env. Also uses ua.DateTime
(a datetime subclass) and ua.UInt32 to satisfy the new stricter types,
with no behavior change (verified via binary encode/decode round-trip).
