fix(test): drop removed logger arg from GalaxyRepositoryGrpcService test call sites; docs: STA phrasing

Remove the trailing NullLogger<GalaxyRepositoryGrpcService>.Instance argument
from all four CreateService/inline constructions in GalaxyRepositoryGrpcServiceTests
and GalaxyFilterInputSafetyTests, matching the now-4-param constructor after the
dead logger parameter was removed in 0032d2d. Also drop the now-unused
Microsoft.Extensions.Logging.Abstractions using from both files.

Rephrase the §5 STA blurb in docs/AlarmClientDiscovery.md: GatewayAlarmMonitor
routes polling *through* the worker's StaRuntime (which owns the STA pump) rather
than owning the pump itself.

docs/AlarmClientDiscovery.md

@@ -770,9 +770,8 @@ on cross-apartment marshaling unless the host STA pumps Win32
 messages. The smoke test sidesteps this by setting
 `pollIntervalMilliseconds=0` (Timer disabled) and driving `PollOnce`
 manually from the test's STA. Production alarm polling was wired up
-through the worker's `StaRuntime` via `GatewayAlarmMonitor`, which
-owns the STA pump and drives alarm subscriptions through the worker
-IPC path. This item is resolved; the wnwrap consumer's `PollOnce`
+through `GatewayAlarmMonitor`, which routes polling through the
+worker's `StaRuntime` (the STA pump owner) via the worker IPC path. This item is resolved; the wnwrap consumer's `PollOnce`
 is no longer invoked directly in production.
 
 ### Capture summary