Phase 0 WP-0.10–0.12: Host skeleton, options classes, sample configs, and execution framework

- WP-0.10: Role-based Host startup (Central=WebApplication, Site=generic Host),
  15 component AddXxx() extension methods, MapCentralUI/MapInboundAPI stubs
- WP-0.11: 12 per-component options classes with config binding
- WP-0.12: Sample appsettings for central and site topologies
- Add execution procedure and checklist template to generate_plans.md
- Add phase-0-checklist.md for execution tracking
- Resolve all 21 open questions from plan generation
- Update IDataConnection with batch ops and IAsyncDisposable
57 tests pass, zero warnings.

Component-DataConnectionLayer.md

@@ -22,13 +22,16 @@ Site clusters only. Central does not interact with machines directly.
 Both OPC UA and LmxProxy implement the same interface:
 
 ```
-IDataConnection
+IDataConnection : IAsyncDisposable
 ├── Connect(connectionDetails) → void
 ├── Disconnect() → void
 ├── Subscribe(tagPath, callback) → subscriptionId
 ├── Unsubscribe(subscriptionId) → void
 ├── Read(tagPath) → value
+├── ReadBatch(tagPaths) → values
 ├── Write(tagPath, value) → void
+├── WriteBatch(values) → void
+├── WriteBatchAndWait(values, flagPath, flagValue, responsePath, responseValue, timeout) → bool
 └── Status → ConnectionHealth
 ```
 
@@ -43,7 +46,10 @@ Additional protocols can be added by implementing this interface.
 | `Subscribe(tagPath, callback)` | OPC UA Monitored Items | `SubscribeAsync(addresses, onUpdate)` → server-streaming gRPC (`IAsyncEnumerable<VtqMessage>`) |
 | `Unsubscribe(id)` | Remove Monitored Item | `ISubscription.DisposeAsync()` (cancels streaming RPC) |
 | `Read(tagPath)` | OPC UA Read | `ReadAsync(address)` → `Vtq` |
+| `ReadBatch(tagPaths)` | OPC UA Read (multiple nodes) | `ReadBatchAsync(addresses)` → `IDictionary<string, Vtq>` |
 | `Write(tagPath, value)` | OPC UA Write | `WriteAsync(address, value)` |
+| `WriteBatch(values)` | OPC UA Write (multiple nodes) | `WriteBatchAsync(values)` |
+| `WriteBatchAndWait(...)` | OPC UA Write + poll for confirmation | `WriteBatchAndWaitAsync(values, flagAddress, flagValue, responseAddress, responseValue, timeout)` |
 | `Status` | OPC UA session state | `IsConnected` property + keep-alive heartbeat (30-second interval via `GetConnectionStateAsync`) |
 
 ### Common Value Type
@@ -84,9 +90,6 @@ LmxProxy is a gRPC-based protocol for communicating with LMX data servers. An ex
 - Subscription disposed via `ISubscription.DisposeAsync()`.
 
 **Additional Capabilities (beyond IDataConnection)**:
-- `ReadBatchAsync(addresses)` — bulk read in a single gRPC call.
-- `WriteBatchAsync(values)` — bulk write in a single gRPC call.
-- `WriteBatchAndWaitAsync(values, flagAddress, flagValue, responseAddress, responseValue, timeout)` — write-and-poll pattern for handshake protocols (default timeout: 30s, poll interval: 100ms).
 - Built-in retry policy via Polly: exponential backoff (base delay × 2^attempt), configurable max attempts (default: 3), applied to reads. Transient errors: `Unavailable`, `DeadlineExceeded`, `ResourceExhausted`, `Aborted`.
 - Operation metrics: count, errors, p95/p99 latency (ring buffer of last 1000 samples per operation).
 - Correlation ID propagation for distributed tracing (configurable header name).