ci(#606): Gitea-compatible trx upload + deterministic fixes for the CI-load test flakes

- v2-ci.yml: upload-artifact@v4 -> @v3 + continue-on-error (act_runner reports as GHES and
  v4 refuses GHES, failing every run); runner-capacity diagnostic step; AKKA_TEST_TIMEFACTOR=3
  on the test step.
- Runtime/ControlPlane harnesses: akka.test.timefactor from AKKA_TEST_TIMEFACTOR
  (TestTimeFactor), single-expect-default 15s; ControlPlane gains PresenceBudget.
- Leaked spinner threads: the infinite-loop timeout tests (Calculation, Host.IntegrationTests
  RoslynVirtualTagEvaluator, 3x Core.Scripting) pinned a core for the rest of the test process
  (abandoned, never stopped). Now a bounded 5 s wall-clock spin; outer compile-inclusive bound 30 s.
- Real test races fixed: ScriptedAlarmEngine push-during-drain (Inactive is also the start
  state + persist-before-update => wait for the Cleared save); DriverReconnectE2e (both nodes
  host the driver; Created[] is last-writer-wins and ForceReconnect is a no-op while
  Connecting); ControlPlaneStarterOrder (lost-race heal waited for a 60 s refresh tick).
- Fixed sleeps -> poll-for-condition: ReconnectSupervisor LastError, Modbus deadband steps
  (wait for observed reads), Modbus dispose hygiene precondition, FOCAS probe-loop log.
- Short presence budgets -> PresenceBudget in the Runtime/ControlPlane tests seen failing on
  Gitea; Calculation Settle 10 -> 30 s. No assertion removed, nothing skipped.
- infra/README.md §10 CI; stale TreatWarningsAsErrors comment in Directory.Build.props.

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DriverHostActorBootFromCacheTests.cs

@@ -75,7 +75,7 @@ public sealed class DriverHostActorBootFromCacheTests : RuntimeActorTestBase
             opcUaPublishActor: publishProbe.Ref,
             deploymentArtifactCache: new StubArtifactCache(cached)));
 
-        var rebuild = publishProbe.ExpectMsg<OpcUaPublishActor.RebuildAddressSpace>(TimeSpan.FromSeconds(5));
+        var rebuild = publishProbe.ExpectMsg<OpcUaPublishActor.RebuildAddressSpace>(PresenceBudget);
         rebuild.Artifact.ShouldNotBeNull();
         rebuild.Artifact.ShouldBe(blob);
     }
@@ -226,7 +226,7 @@ public sealed class DriverHostActorBootFromCacheTests : RuntimeActorTestBase
         // The point: the restore path wrote the served artifact back into the cache.
         AwaitAssert(
             () => cache.Stores.ShouldBe(1),
-            duration: TimeSpan.FromSeconds(5));
+            duration: PresenceBudget);
         cache.LastStoredDeploymentId.ShouldBe(deploymentId.ToString());
     }
 
@@ -241,10 +241,10 @@ public sealed class DriverHostActorBootFromCacheTests : RuntimeActorTestBase
                 actor.Tell(new GetDiagnostics(CorrelationId.NewId()), probe.Ref);
                 probe.ExpectMsg<NodeDiagnosticsSnapshot>(TimeSpan.FromSeconds(2));
             },
-            duration: TimeSpan.FromSeconds(5));
+            duration: PresenceBudget);
 
         actor.Tell(new GetDiagnostics(CorrelationId.NewId()), probe.Ref);
-        return probe.ExpectMsg<NodeDiagnosticsSnapshot>(TimeSpan.FromSeconds(5));
+        return probe.ExpectMsg<NodeDiagnosticsSnapshot>(PresenceBudget);
     }
 
     /// <summary>A syntactically valid artifact with no driver instances.</summary>