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

.github/workflows/v2-ci.yml

@@ -52,6 +52,13 @@ jobs:
           dotnet-version: 10.0.x
       - name: dotnet restore
         run: dotnet restore ZB.MOM.WW.OtOpcUa.slnx
+      # #606: the runner's size is the context every timing-sensitive failure needs and the log never
+      # recorded it (load average included: the two Gitea runners may be running jobs side by side).
+      - name: runner capacity
+        run: |
+          echo "nproc=$(nproc)"
+          free -m || true
+          uptime || true
       # 07/S-1: ONE whole-solution leg instead of a hand-maintained 5-project matrix that
       # silently dropped Client (388 tests), Analyzers (31), and every driver + most Core suite.
       # Self-maintaining — a new *.Tests project is covered automatically, no matrix to widen —
@@ -61,6 +68,13 @@ jobs:
       # excluded here — it is a local-dev-loop opt-out only. The skip-gated *.IntegrationTests Assert.Skip when their fixtures
       # are unreachable, so they run harmlessly here (and are counted by the skip-gate below).
       - name: dotnet test (whole solution, minus E2E + LiveIntegration)
+        # #606: Akka TestKit time dilation for the Runtime + ControlPlane actor suites (read by their
+        # harnesses, tests/Server/*/Harness/TestTimeFactor.cs). This leg runs every test assembly at once
+        # on the runner, and their 2–8 s presence budgets — sized on an idle dev box — failed in a long
+        # tail, a different test per run. Dilation only stretches waits: a presence wait still fails if
+        # the message never comes, and absence windows get longer (stricter). Local runs stay at 1.
+        env:
+          AKKA_TEST_TIMEFACTOR: "3"
         run: >
           dotnet test ZB.MOM.WW.OtOpcUa.slnx --configuration Release --no-restore
           --filter "Category!=E2E&Category!=LiveIntegration"
@@ -71,9 +85,16 @@ jobs:
       - name: assert not-all-skipped
         if: always()
         run: bash scripts/ci/assert-not-all-skipped.sh artifacts/trx/*.trx
+      # #606: pinned to v3. Gitea's act_runner reports itself as GHES, and @actions/artifact v2+
+      # (upload-artifact@v4+) refuses GHES outright ("GHESNotSupportedError") — so on Gitea the v4
+      # step failed EVERY run and the job could never go green, independent of the tests. v3 speaks
+      # the artifact API Gitea implements. continue-on-error because the trx upload is evidence, not a
+      # gate: the test step and the skip-gate above decide the job, and an artifact-store hiccup must
+      # not turn a green run red.
       - name: upload trx
         if: always()
-        uses: actions/upload-artifact@v4
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
         with:
           name: unit-trx
           path: artifacts/trx/*.trx