Add gateway implementation planning docs

gateway.md

@@ -40,6 +40,37 @@ The worker does not host gRPC. The gateway talks to workers through a small
 local IPC protocol. Named pipes with protobuf-framed messages are the default
 transport.
 
+Detailed follow-up docs:
+
+- `docs/gateway-process-design.md` covers the .NET 10 gateway process,
+  session manager, worker supervision, gRPC API, event streaming, fault model,
+  security, observability, and test strategy.
+- `docs/mxaccess-worker-instance-design.md` covers each .NET Framework 4.8 x86
+  MXAccess worker instance, including STA ownership, message pumping, COM
+  lifetime, command dispatch, event sinks, conversion, and shutdown.
+- `docs/design-decisions.md` records current v1 choices, including API-key
+  authentication in gateway-owned SQLite and the concrete installed MXAccess
+  COM class details from `C:\Users\dohertj2\Desktop\mxaccess`.
+- `docs/gateway-dashboard-design.md` covers the Blazor Server and Bootstrap
+  dashboard for live gateway/session/worker status.
+- `docs/client-libraries-design.md` covers shared design requirements for
+  official gRPC client libraries, test CLIs, and tests for .NET C#, Go, Rust,
+  Python, and Java.
+- `docs/implementation-plan-index.md` links the detailed implementation plans
+  and recommended Gitea milestones/issues.
+
+Implementation style guides:
+
+- `StyleGuide.md` covers project documentation.
+- `docs/style-guides/CSharpStyleGuide.md` covers gateway, worker, .NET client,
+  and C# tests.
+- `docs/style-guides/ProtobufStyleGuide.md` covers public gRPC and worker IPC
+  contracts.
+- `docs/style-guides/GoStyleGuide.md` covers the Go client.
+- `docs/style-guides/RustStyleGuide.md` covers the Rust client.
+- `docs/style-guides/PythonStyleGuide.md` covers the Python client.
+- `docs/style-guides/JavaStyleGuide.md` covers the Java client.
+
 ## Process Split
 
 ### Gateway Process
@@ -866,16 +897,30 @@ backend = mxaccess-worker
 
 ## Open Questions
 
-- Exact installed MXAccess COM ProgID/class used by production should be pinned
-  from the existing trace harness.
-- Whether one gRPC client connection maps to one session or whether sessions can
-  survive client reconnects.
-- Whether event streams can have multiple subscribers per session.
-- Required authentication model for remote clients.
-- Whether worker process identity should be the gateway identity or a restricted
-  service account.
-- Maximum supported event rate before coalescing is required.
-- Whether command batching is needed for high-volume tag registration.
+Current v1 decisions are recorded in `docs/design-decisions.md`.
+
+Resolved for v1:
+
+- MXAccess COM target is `ArchestrA.MxAccess.LMXProxyServerClass` /
+  `LMXProxy.LMXProxyServer.1` from the installed 32-bit `LmxProxy.dll`.
+- One `OpenSession` maps to one worker process; no reconnectable sessions.
+- One active event subscriber per session.
+- API key authentication with hashed keys in gateway-owned SQLite.
+- Basic Blazor Server dashboard with Bootstrap CSS/JS and real-time updates.
+- Workers run as the gateway service identity.
+- Event backpressure is fail-fast with bounded queues.
+- No public command batching.
+- `OperationComplete` is forwarded only when native MXAccess raises it.
+- `OnBufferedDataChange` is modeled now; multi-sample payload conversion remains
+  capture-validated work.
+
+Post-v1 revisit items:
+
+- production event-rate target and optional coalescing,
+- reconnectable sessions,
+- multi-subscriber event fan-out,
+- restricted worker process identity,
+- command batching for high-volume setup.
 
 ## Recommended Next Step