NATS Migration: Binary Protocol to NATS/JetStream

The current ores.comms.service monolith connects Qt clients via a custom binary protocol over ASIO SSL. Request/reply is fully serialised. The target architecture uses NATS with JetStream as the sole message bus. Every dialog communicates independently and concurrently. Server push becomes plain pub/sub. Chart history uses JetStream replay. Grid nodes (client- and server-side) consume work from JetStream queues.

Each domain becomes its own standalone service (ores.iam.service, ores.refdata.service, etc.) that connects directly to NATS. There is no central gateway or proxy — NATS is the bus.

Constraints:

• Each PR must compile cleanly and all tests must pass
• The system may be non-functional between PRs — no backwards compatibility required
• Services follow the existing naming convention: ores.<domain>.service
• No dual-mode / parallel-path code
• NNG is already partially implemented in main and must be removed

PR: [cleanup] Remove NNG broker and NNG service runner

NNG is partially implemented in main but never shipped to users. Remove it cleanly before starting NATS work.

Working state: Clean main with no NNG code. All existing tests pass. ores.comms.service still runs normally over ASIO SSL.

PR: [nats] Add cnats dependency and ores.nats foundation library

Working state: ores.nats compiles and links. No functional change anywhere. All existing tests pass.

Risk: cnats delivers subscription callbacks on internal threads — not the Qt main thread. nats_client must post callbacks to the Qt event loop via QMetaObject::invokeMethod(..., Qt::QueuedConnection). Design this in from the start.

PR: [nats] Replace ASIO SSL server in ores.comms.service with NATS

ores.comms.service keeps all domain handler logic unchanged. Only the transport layer is replaced: the ASIO SSL server is removed and nats_service_base subscriptions replace it for all message type ranges.

System state: Qt client is broken (still uses ASIO). Handler unit tests pass — handlers operate on bytes with no transport dependency. ores.comms.service connects to NATS and handles messages correctly.

Do not delete ores.comms/net/ yet — the Qt client and shell still depend on it.

PR: [nats] Replace ASIO SSL client in ores.qt and ores.comms.shell with NATS

System state: Qt and shell connect via NATS. Login and all dialogs work again. All tests pass.

PR: [arch] Split ores.comms.service into standalone domain services

Each domain becomes a standalone executable following the ores.<domain>.service naming convention. Each service:

• Has its own main.cpp, config/options.hpp, config/parser.cpp
• Extends nats_service_base
• Subscribes only to its own message type subjects
• Holds its own database connection pool (size 1-2)
• Links only the libraries it needs (no cross-domain dependencies)

Then:

• Delete projects/ores.comms.service/
• Update projects/CMakeLists.txt
• Update ores-prodigy.el: replace single comms-service entry with one entry per domain service

Risk: DB connections multiply ~10×. Set pool size to 1-2 per service and verify PostgreSQL max_connections is sufficient before starting.

System state: Fully decomposed. Each service starts independently. All tests pass.

PR: [nats] Replace server push with NATS pub/sub subscriptions

• Each domain service publishes to ores.<tenant>.<domain>.events.<type> when entities change (hook into the existing ores.eventing event bus as a NATS publisher)
• Qt dialogs subscribe to relevant subjects via nats_client
• ClientManager notification callback wired to NATS subscription delivery

System state: Live entity updates delivered via NATS pub/sub.

PR: [nats] Add JetStream streams for chart history and live data

• Define JetStream stream configs: ORES_TRADES, ORES_PRICES, etc.
• Domain services publish to JetStream subjects on entity changes
• Qt chart widgets create JetStream consumer with DeliverByStartTime for history, seamlessly continuing live on the same consumer
• js_consumer.hpp (stubbed in Phase 2) fully implemented

System state: Charts show history + live data. New capability.

Phase 1: Remove NNG from main        (cleanup, system unchanged)
Phase 2: ores.nats library           (additive, system unchanged)
Phase 3: comms.service → NATS        (system broken: Qt still ASIO)
Phase 4: Qt + shell → NATS           (system restored)
Phase 5: Split monolith              (decompose into ores.*.service)
Phase 6: Pub/sub events              (new capability)
Phase 7: JetStream charts            (new capability)