Implements ApiRateLimiter with SemaphoreSlim-based concurrency limiting (default 256 slots)
and ConcurrentDictionary dedup cache keyed by request ID with configurable TTL, matching
Go's jetstream_api.go maxConcurrentRequests semaphore and dedup window. Also adds
ClusteredRequestProcessor for correlating pending RAFT proposals with waiting callers via
TaskCompletionSource, and SlopwatchSuppressAttribute as a marker for intentional timing-based
tests. 12 ApiRateLimiter tests + 13 ClusteredRequestProcessor tests all pass.
Implement HandleClusteredCreateAsync, HandleClusteredUpdateAsync, and
HandleClusteredDeleteAsync on StreamApiHandlers, and HandleClusteredCreateAsync
and HandleClusteredDeleteAsync on ConsumerApiHandlers. These handlers propose
operations to the meta RAFT group (JetStreamMetaGroup) instead of operating on
the local StreamManager/ConsumerManager, matching the Go jsClusteredStreamRequest
and jsClusteredConsumerRequest patterns (jetstream_cluster.go:7620-8265).
Ten tests in ClusteredApiTests.cs verify: stream create proposes to meta group,
duplicate-stream error, not-leader error (code 10003), stream update, stream
delete, not-found-on-delete, consumer create on stream, consumer-on-missing-stream
error, consumer delete, and not-found consumer delete.
Add ILeaderForwarder interface and DefaultLeaderForwarder, update
JetStreamApiRouter with RouteAsync + ForwardedCount so non-leader nodes
can attempt to forward mutating requests to the meta-group leader before
falling back to a NotLeader error response.
Stream lifecycle, publish/ack, consumer delivery, retention policy,
API endpoints, cluster formation, and leader failover tests ported
from Go nats-server reference. 1006 total tests passing.
