ci(v2): whole-solution unit leg + fail-on-skip gate + deflake CLI sleeps (arch-review 07/S-1,S-2,S-4)

S-1: replace the hand-maintained 5-project unit-tests matrix (which silently dropped
Client's 388 tests, Analyzers' 31, and every driver + most Core suite) with ONE
whole-solution leg — dotnet test ZB.MOM.WW.OtOpcUa.slnx --filter
"Category!=E2E&Category!=LiveIntegration". Self-maintaining: a new *.Tests project is
covered automatically, matching CLAUDE.md's own guidance.

S-2: emit trx + add scripts/ci/assert-not-all-skipped.sh, a fail-on-skip gate that
turns 'green CI == everything skipped' into a red build. Wired strict (MIN_EXECUTED=1)
on the unit leg; report-only (MIN_EXECUTED=0) on the fixtureless integration leg so
its skip tally is VISIBLE without a false red — with a documented follow-up to start
the one public-image fixture (opc-plc) as a service and flip it strict.

S-4 (paired): the newly-CI'd Client.CLI.Tests had fixed-sleep startup races
(await Task.Delay(100/150) before cancelling a background command) that would flake
under CI load. Added SubscribeInvoked / SubscribeAlarmsInvoked readiness signals
(TaskCompletionSource) to FakeOpcUaClientService and replaced the 11 sleeps across
AlarmsCommandTests / SubscribeCommandTests / EventHandlerLifecycleTests with a
deterministic await-the-signal (10s timeout guard).

Verified: workflow YAML parses; skip-gate proven locally on a real trx (executed=31
=> OK), a synthetic all-skipped trx (executed=0 => exit 1 with diagnostic),
report-only mode (never fails), multi-file sum, and missing-file (exit 2);
Client.CLI.Tests 104/104 green after the deflake. (CI job execution itself is
verifiable only on push — nothing pushed.)

scripts/ci/assert-not-all-skipped.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+#
+# assert-not-all-skipped.sh — arch-review 07/S-2 fail-on-skip guard.
+#
+# A CI test leg that ran but executed ZERO tests reports success, so a whole tier
+# silently skipping (fixtures unreachable, a --filter that matched nothing, a probe
+# that Assert.Skip'd every case) is indistinguishable from a real pass. This gate
+# reads the trx result summary and FAILS when fewer than MIN_EXECUTED tests actually
+# ran across the supplied trx files — turning "green means skipped" into a red build.
+#
+# Usage:   scripts/ci/assert-not-all-skipped.sh <trx> [<trx> ...]
+# Env:     MIN_EXECUTED  minimum executed tests required (default 1).
+#                        Set MIN_EXECUTED=0 for a report-only pass (never fails) —
+#                        used by the fixtureless integration leg until its fixtures
+#                        run as workflow services (S-2 option #2 follow-up).
+#
+set -euo pipefail
+
+min_executed="${MIN_EXECUTED:-1}"
+
+if [ "$#" -eq 0 ]; then
+  echo "assert-not-all-skipped: no trx files given" >&2
+  exit 2
+fi
+
+total_executed=0
+total_skipped=0
+seen=0
+
+for f in "$@"; do
+  if [ ! -f "$f" ]; then
+    echo "assert-not-all-skipped: trx not found: $f" >&2
+    exit 2
+  fi
+  seen=$((seen + 1))
+  # The trx <Counters .../> element in <ResultSummary> carries executed + notExecuted counts.
+  counters="$(grep -oE '<Counters[^>]*/?>' "$f" | head -1)"
+  ex="$(printf '%s' "$counters" | grep -oE 'executed="[0-9]+"' | grep -oE '[0-9]+' || true)"
+  ne="$(printf '%s' "$counters" | grep -oE 'notExecuted="[0-9]+"' | grep -oE '[0-9]+' || true)"
+  ex="${ex:-0}"
+  ne="${ne:-0}"
+  total_executed=$((total_executed + ex))
+  total_skipped=$((total_skipped + ne))
+  echo "  $(basename "$f"): executed=${ex} skipped=${ne}"
+done
+
+echo "assert-not-all-skipped: files=${seen} executed=${total_executed} skipped=${total_skipped} (min required=${min_executed})"
+
+if [ "$total_executed" -lt "$min_executed" ]; then
+  echo "::error::CI executed ${total_executed} test(s) (< ${min_executed}) — the tier ran nothing (all skipped?). Treating as FAILURE, not a pass." >&2
+  exit 1
+fi
+
+echo "assert-not-all-skipped: OK"