fix(scripting): quarantine a refusal behind a stuck orphan (fix round 2)

Ruling refinement on I1. Only timeouts are strikes, so a never-returning
while(true), which times out once and is then only refused, was never
quarantined, and that defeated E1. A refusal now quarantines immediately
when the orphan it was refused behind has been executing for longer than
ScriptingOptions.StuckOrphanQuarantineFactor x the script's timeout
(default 10, so 20 s at the 2 s default; 0 or less disables it). It uses
the same quarantine path: one Error, otopcua.script.quarantined with
reason=stuck, Bad, lifted on source change or redeploy. A young orphan
(a short overrun) is still a plain refusal.

The guard stamps the run's start (Stopwatch timestamp) when the pool
picks it up and clears it when the run really finishes.

Tests: the 30-trigger while(true) regression (paced) now ends
quarantined with reason "stuck", still with exactly one orphan and a
healthy sibling. Positive control: a 2x overrun is refused, not
quarantined, and evaluates again once the orphan completes. A factor of
0 disables the rule. Docs (ScriptEditor "Runtime safety", VirtualTags)
and the seam remarks are updated.

Refs #734

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

src/Server/ZB.MOM.WW.OtOpcUa.Host/Engines/RoslynVirtualTagEvaluator.cs

@@ -35,7 +35,7 @@ namespace ZB.MOM.WW.OtOpcUa.Host.Engines;
 ///     <b>Run quarantine.</b> Every compiled run goes through one <see cref="ScriptRunGuard"/> keyed by
 ///     virtual-tag id with the expression as the source identity: a run is refused while the tag's previous
 ///     (timed-out, abandoned) run is still executing, and the tag is quarantined after three consecutive
-///     timeouts (a refusal is Bad but not a strike) or an allocation-budget breach. Both surface as <see cref="VirtualTagEvalResult.Failure"/>
+///     timeouts (a refusal is Bad but not a strike, unless its orphan is stuck past StuckOrphanQuarantineFactor × the budget) or an allocation-budget breach. Both surface as <see cref="VirtualTagEvalResult.Failure"/>
 ///     so <c>VirtualTagActor</c> publishes Bad exactly as it does for a timeout. A quarantine lifts when the
 ///     expression changes, on <see cref="ClearCompiledScripts"/> / <see cref="ResetQuarantines"/> (the deploy
 ///     boundary), never by itself.