fix(audit): populate ParentExecutionId on alarm-triggered script runs

M5.4 T4 threaded a `parentExecutionId` parameter through
AlarmActor.SpawnAlarmExecution → AlarmExecutionActor → ScriptRuntimeContext,
but every call site passed null — so alarm on-trigger runs were silently always
execution-tree roots, contradicting the "tag-cascade coverage is complete"
claim in CLAUDE.md and Component-AuditLog.md.

Source the id where a spawner genuinely exists: a static attribute write issued
by a site script (`Instance.SetAttribute`) or by an inbound API request
(`Route.To(...).SetAttributes(...)`, whose ParentExecutionId was already carried
to the site and then dropped). The id rides site-locally through three additive,
nullable fields — no wire, proto or central schema change:

  ScriptRuntimeContext.SetAttribute / RouteToSetAttributesRequest.ParentExecutionId
    → SetStaticAttributeCommand.SourceExecutionId
    → AttributeValueChanged.SourceExecutionId   (InstanceActor static-write path)
    → AlarmActor.SpawnAlarmExecution → AlarmExecutionActor → ScriptRuntimeContext

All four computed trigger types participate. Expression triggers evaluate off
the dispatcher, so the writer of the newest value folded into the snapshot is
captured *with* the snapshot and echoed home on ExpressionEvalResult /
ExpressionEvalFailed — a change arriving mid-flight cannot mis-attribute the
raise.

Deliberately still roots (documented, not deferred): alarms fired by Data
Connection Layer values (external device data has no spawning execution — this
includes the device echo of a script write to a *data-sourced* attribute, so
only static writes cascade), and ScriptActor value-change/conditional/
expression/timer trigger runs (a timer tick has no spawner; a WhileTrue/interval
run has no single identifiable write).

Tests: new SiteRuntime.Tests/Actors/AlarmCascadeParentExecutionTests pins all
three hops — SetAttribute stamps the run's ExecutionId, InstanceActor publishes
it on the change (and publishes null when absent), and ValueMatch/HiLo/
Expression alarms parent the on-trigger run to the writer while a DCL-originated
change leaves it a root.

Docs: CLAUDE.md and Component-AuditLog.md corrected from "complete" to the true
behaviour; Component-SiteRuntime.md gains an "Audit correlation of an on-trigger
run" section with the hop table and the by-design root cases.

CLAUDE.md

@@ -149,7 +149,7 @@ spec for each is `docs/requirements/Component-<Name>.md`, and `README.md` carrie
 - Scope = script trust boundary: outbound API (sync + cached), outbound DB (sync + cached), notifications, inbound API. Framework/internal traffic is explicitly excluded.
 - One row per lifecycle event; cached calls produce 4+ rows per operation (`Submitted`, `Forwarded`, `Attempted`, `Delivered`/`Parked`/`Discarded`).
 - `ExecutionId` (`uniqueidentifier NULL`) is the universal per-run correlation value — every audit row emitted by one script execution / inbound request shares it; `CorrelationId` remains the per-operation lifecycle id (NULL for sync one-shots).
-- `ParentExecutionId` (`uniqueidentifier NULL`) is the cross-execution spawn pointer — every row of a spawned run carries the spawner's `ExecutionId`; bridges inbound API → routed-site-script, alarm-triggered on-trigger scripts, and nested `CallScript`/`CallShared` invocations; `IX_AuditLog_ParentExecution` backs the filter + the recursive execution-tree walk. Tag-cascade coverage is complete as of M5.4 (T4) — no further spawn points are deferred.
+- `ParentExecutionId` (`uniqueidentifier NULL`) is the cross-execution spawn pointer — every row of a spawned run carries the spawner's `ExecutionId`; bridges inbound API → routed-site-script, alarm-triggered on-trigger scripts, and nested `CallScript`/`CallShared` invocations; `IX_AuditLog_ParentExecution` backs the filter + the recursive execution-tree walk. **Tag-cascade (alarm leg) is populated, not just plumbed** — M5.4 T4 threaded the `parentExecutionId` parameter but every `AlarmActor.SpawnAlarmExecution` call site passed null, so alarm runs were silently always roots; the id now rides site-locally as `SetStaticAttributeCommand.SourceExecutionId` → `AttributeValueChanged.SourceExecutionId` → `SpawnAlarmExecution` (all additive/nullable, no wire/proto/schema change; `Expression` triggers capture the writer *with* the evaluated snapshot since the eval completes off-dispatcher). Sources are `ScriptRuntimeContext.SetAttribute` (the run's own `ExecutionId`) and `Route.To(...).SetAttributes(...)` (the inbound request's). **Still roots by design, not omission:** alarms fired by DCL data (external values have no spawning execution — including the device echo of a script write to a *data-sourced* attribute, so only **static** writes cascade), and `ScriptActor` value-change/conditional/expression/timer trigger runs (a timer tick has no spawner; a `WhileTrue`/interval run has no single identifiable write).
 - Site SQLite hot-path first, then gRPC telemetry to central; ingest is idempotent on `EventId`; periodic reconciliation pull as fallback when telemetry is lost.
 - Cached operations: site emits a single additively-extended `CachedCallTelemetry` packet carrying both audit events and operational state; central writes `AuditLog` + `SiteCalls` in one transaction.
 - Payload cap 8 KB by default / 64 KB on error rows; auth headers redacted by default; SQL parameter values captured by default; per-target redaction opt-in. Inbound API: full verbatim capture up to `InboundMaxBytes` (default 1 MiB); request headers stored in `Extra.requestHeaders` (post-redaction); per-method `SkipBodyCapture` flag suppresses bodies while still recording headers + metadata; `AuditInboundCeilingHits` counter surfaced on health snapshot. (M5.3 T7)