v2.12.3

## Changelog

Refer to the [2.12 Upgrade Guide](https://docs.nats.io/release-notes/whats_new/whats_new_212) for backwards compatibility notes with 2.11.x.

### Go Version

- 1.25.5 (#7604)

### Dependencies

- github.com/google/go-tpm v0.9.7 (#7578)
- github.com/nats-io/nkeys v0.4.12 (#7578)
- golang.org/x/crypto v0.45.0 (#7578)
- github.com/klauspost/compress v1.18.2 (#7604)
- github.com/antithesishq/antithesis-sdk-go v0.5.0-default-no-op (#7604)
- golang.org/x/crypto v0.46.0 (#7648)
- golang.org/x/sys v0.39.0 (#7648)

### Added

General

- Added WebSocket-specific ping interval configuration with `ping_internal` in the `websocket` block (#7614)

### Improved

JetStream

- The scan for the last sourced message sequence when setting up a subject-filtered source is now considerably faster (#7553)
- The metalayer will now stage and deduplicate recovery operations at startup, instead of rapidly applying and then undoing conflicting assignments (#7540)
- Consumer interest checks on interest-based streams are now significantly faster when there are large gaps in interest (#7656)

MQTT

- Retained messages will now work correctly even when sourced from a different account and has a subject transform (#7636)

### Fixed

General

- WebSocket connections will now correctly limit the buffer size during decompression (#7625, thanks to Pavel Kokout at Aisle Research)

JetStream

- A protocol error caused by an invalid transform of acknowledgement reply subjects when originating from a gateway connection has been fixed (#7579)
- The meta layer will now only respond to peer remove requests after quorum has been reached (#7581)
- Invalid subject filters containing non-terminating full wildcard no longer produce unexpected matches (#7585)
- A data race when creating a stream in clustered mode has been fixed (#7586)
- Raft will no longer allow multiple membership changes to take place concurrently (#7565, #7609)
- A panic when processing snapshots with missing nodes or assignments has been fixed (#7588)
- When purging whole message blocks, the subject tracking and scheduled messages are now updated correctly (#7593)
- Raft will no longer count responses from peer-removed nodes towards quorum (#7589)
- The filestore will no longer unexpectedly lose writes when `AsyncFlush` is enabled after a process pause (#7594)
- The filestore now will process message removal on disk before updating accounting, which improves error handling (#7595, #7601)
- Raft quorum counting has been refactored so the implicit leader ack is now only counted if still a part of the membership (#7600)
- Raft now writes the peer state immediately when handling a peer-remove to ensure the removed peers cannot unexpectedly reappear after a restart (#7602)
- The `DiscardNewPerSubject` retention policy is now enforced by the leader before proposing rather than by individual replicas, reducing the potential for stream desync (#7607)
- Raft will no longer allow peer-removing the one remaining peer (#7610)
- A data race has been fixed in the stream health check (#7619)
- Tombstones are now correctly written for recovering the sequences after compacting or purging an almost-empty stream to seq 2 (#7627)
- Combining skip sequences and compactions will no longer overwrite the block at the wrong offset, correcting a `corrupt record state` error (#7627)
- Compactions that reclaim over half of the available space now use an atomic write to avoid losing messages if killed (#7627)
- Filestore message lookups will now expire the cache if a cache error is encountered (#7630)
- Improved error handling within the loading of message blocks if not already cached (#7631)
- Add peer operations to Raft can no longer result in disjoint majorities (#7632)
- Filestore compaction should no longer result in `no idx present` cache errors (#7634)
- Filestore compaction now correctly adjusts the high and low sequences for a message block, as well as cleaning up the deletion map accordingly (#7634)
- Raft groups should no longer readmit a previously removed peer if a heartbeat occurs between the peer removal and the leadership transfer (#7649)
- Potential stream desyncs that could happen during stream snapshotting have been fixed (#7655)

MQTT

- The maximum payload size is now correctly enforced for MQTT clients (#7555, thanks to @yixianOu)
- Fixed a panic that could occur when reloading config if the user did not have permission to access retained messages (#7596)
- Fixed account mapping for JetStream API requests when traversing non-JetStream-enabled servers (#7598)
- QoS0 messages are now mapped correctly across account imports/exports with subject mappings (#7605)
- Loading retained messages no longer fails after restarting due to last sequence checks (#7616)
- A bug which could corrupt retained messages in clustered deployments has been fixed (#7622)
- Permissions to `$MQTT.` subscriptions are now handled implicitly, with the exception of `deny` ACLs which still permit restriction (#7637)
- A bug where QoS2 messages could not be retrieved after a server restart has been fixed (#7643)

### Complete Changes
 
https://github.com/nats-io/nats-server/compare/v2.12.2...v2.12.3