feat(focas): CNC alarms reach Part 9 conditions via ALARM: tags (#647)

An ALARM: address (*, <Type>, <Type>/<n>, <Type>/<lo>-<hi>, T<code>, OTHER) on a raw tag that
also carries the cross-driver alarm object is ONE condition with ConditionId == RawPath and a
Kind (Raise / Retrigger / Clear), so DriverHostActor.ForwardNativeAlarm routes it and
NativeAlarmProjector activates it. Fixes all seven triage defects:

1. SubscribeAlarmsAsync treated the host's RawPaths as device hosts -> nothing polled.
2. Decorated "{host}#{Type}:{Number}" ConditionId -> every event dropped.
3. No Kind -> projector kept prior state.
4. WireFocasClient.ReadAlarmsAsync answered [] on failure -> mass clear + un-acked re-raise.
   It now throws; a failed device read keeps every condition's state.
5. Acks lost on reconnect -> told-record dedup (MTConnect #626 pattern) held for the driver's
   lifetime; same-set re-subscribe / re-init re-raise nothing; changed set prunes leavers only.
6. Subscribe threw while AlarmProjection.Enabled=false -> the tag is the opt-in; flag is a no-op.
7. Alarm tags could not be authored -> ALARM: grammar (FocasAlarmSelector, Contracts) backs the
   editor, the address picker, the deploy-time inspector and driver init.

Severity: authored alarm.severity -> exact OpcUaSeverity; else the 16i-era type bucket. The type
table stays the only one (moved to Contracts, documented 16i-era; 30i codes not invented; raw
T<code> selector + raw code in every message). Read-only: ack is server-side. Also clears the
value table on a re-initialise (#630 gap that let a removed/moved tag keep reading).

E2E: Runtime.Tests FocasNativeAlarmEndToEndTests drives the real driver through the real
DriverHostActor and asserts the condition goes Active then inactive.

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

docs/AlarmTracking.md

@@ -56,7 +56,8 @@ same condition is wired as an **event notifier of every referencing equipment fo
   identity RawPath + condition NodeId) with the equipment list as display metadata.
 - **Routing is an exact `ConditionId == RawPath` match** (`DriverHostActor.ForwardNativeAlarm`). A driver that
   decorates the id has every transition dropped as "no alarm condition" — AbCip did (`"{ref}#active"`, fixed
-  under #641); FOCAS still does (see `drivers/FOCAS.md`). A native source must also set `Kind`: an
+  under #641), and so did FOCAS (`"{host}#{Type}:{Number}"`, fixed under #647 — one condition per `ALARM:` tag, see
+  `drivers/FOCAS.md`). A native source must also set `Kind`: an
   `Unspecified` kind projects no state change.
 
 ### Native condition state survives a full rebuild (Gitea #641)