fix(inbound): authorize+secure Database helper, async/deadline-bound DB, wait-timeout-bound WaitForAttribute

Resolves InboundAPI-026/027/028/029 (+ newly-surfaced -030).

- 026: authorize the scoped Database helper in the design doc; SQL-injection
  protection is parameter binding (values never concatenated); allow writes via
  ExecuteAsync; drop the false 'read-only' claim. Named connections only.
- 027: async ADO.NET end-to-end (no .GetAwaiter().GetResult()); honour the method
  deadline token on ExecuteScalarAsync/ExecuteReaderAsync/ExecuteNonQueryAsync +
  a CommandTimeout backstop derived from the method timeout.
- 028: negative-path tests (null-gateway, deadline cancellation, parameterization)
  + e2e Database + WaitForAttribute cases through the real endpoint.
- 029: WaitForAttribute is bounded by its WAIT timeout (per-wait CTS + client-abort
  + explicit token), NOT the method deadline (spec §6) — a long wait may outlive the
  method timeout; WithRequestAborted threads the raw client-abort token separately.
- 030: Central UI compile-surface mirrors (InboundScriptHost / SandboxInboundScriptHost)
  gained the Database member (drifted since the runtime helper was added) so the
  authorized async API type-checks at the design-time gate.

tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorTests.cs

@@ -549,7 +549,7 @@ public class InboundScriptExecutorTests
     [Fact]
     public async Task Script_UsingDatabase_QueriesViaGateway()
     {
-        // A script that calls Database.QuerySingle runs against an executor whose
+        // A script that calls Database.QuerySingleAsync runs against an executor whose
         // ServiceProvider registers an IDatabaseGateway backed by in-memory SQLite.
         var services = new ServiceCollection();
         services.AddSingleton<IDatabaseGateway>(SeededSqliteGateway());
@@ -560,7 +560,7 @@ public class InboundScriptExecutorTests
 
         var method = new ApiMethod(
             "movein",
-            "return new { v = Database.QuerySingle<string>(\"BTDB\", \"SELECT Code FROM Machine WHERE SAPID=@s\", new { s = (string)Parameters[\"sap\"] }) };")
+            "return new { v = await Database.QuerySingleAsync<string>(\"BTDB\", \"SELECT Code FROM Machine WHERE SAPID=@s\", new { s = (string)Parameters[\"sap\"] }) };")
         {
             Id = 1,
             TimeoutSeconds = 10,