v2.12.1

## 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

- 1.25.3 (#7428)

### Dependencies

- github.com/google/go-tpm v0.9.6 (#7374)
- github.com/nats-io/nats.go v1.46.0 (#7374)
- golang.org/x/crypto v0.43.0 (#7423)
- golang.org/x/sys v0.37.0 (#7423)
- golang.org/x/time v0.14.0 (#7423)

### Added

General

- The `NewServerFromConfig` function has been added to the embedded server API for parsing an external configuration file when `ConfigFile` is supplied (#7364)
- WebSocket leafnode connections can now use a HTTP proxy by specifying `proxy` settings in the leafnode `remotes` (#7242)
- The `write_deadline` option in the `cluster`, `leafnode` and `gateway` config blocks allows configuring write deadlines on a finger-grained basis (#7405)

### Improved

Monitoring

- The `jsz` monitoring endpoint can now report leader counts (#7429)

JetStream

- The store lock is no longer held while searching for TTL expiry tasks, improving performance (#7344)
- Removing a message from the TTL state is now faster (#7344)
- The filestore no longer performs heap allocations for hash checks (#7345)
- The filestore now reuses pooled write cache allocations more efficiently (#7346)
- Meta snapshot performance for a very large number of assets has been improved after a regression in v2.11.9 (#7350)
- Sequence-from-timestamp lookups, such as those using `opt_start_time` on consumers or `start_time` on message get requests, now use a binary search for improved lookup performance (#7357)
- Scheduled messages are now deactivated properly when followed up with another message on the same subject without a schedule (#7366)
- Meta snapshots are no longer taken on every stream removal (#7373)
- Filestore cache lookups can now return early for empty blocks (#7381)
- Filestore meta files are now written using temporary staging, avoiding accidental truncation on crashes (#7388)
- Atomic batch publish now supports deduplication with the `Nats-Msg-Id` header (#7391)
- Cache-specific log lines in the filestore have been improved (#7396)
- Log lines and errors related to offline/unsupported assets are now clearer (#7416, #7425)

### Fixed

General

- Fixed the exit code when receiving a `SIGTERM` signal immediately after startup (#7367)
- The `$SYS.REQ.CLAIMS.DELETE` endpoint now correctly strips headers, like the `$SYS.REQ.CLAIMS.UPDATE` endpoint already does (#7413)
- Log lines generated when reloading trusted proxies now report the correct keys (#7427)

JetStream

- Batch check now uses the correct subject instead of the last subject that does the commit (#7342)
- Removed messages with a per-message TTL are now removed from the TTL state immediately (#7344)
- Fixed a bug where TTL state was recovered on startup with subject delete markers enabled, that message expiry would not start as expected (#7344)
- Expiring messages from the filestore no longer leaks timers and expires at the correct time (#7344)
- Fixed a bug where scheduled messages would not trigger correctly after recovery (#7347)
- Deleting a non-existent sequence on a stream no longer results in a cluster reset and leadership election (#7348)
- Subject tree intersection now correctly handles overlapping literals and partial wildcards, i.e. `stream.A` and `stream.*.A`, fixing some consumer or message get filters (#7349)
- A data race when checking all JetStream limits has been fixed (#7356)
- Raft will no longer trigger a reset of the clustered state due to a stream snapshot timeout (#7293)
- Atomic batches now reject unsupported commits (#7368)
- Race conditions and potential panics fixed in the handling of some JetStream API handlers (#7380)
- The filestore no longer loses tombstones when using secure erase (#7384)
- The filestore no longer loses the last sequence when recovering blocks containing only tombstones (#7384)
- The filestore now correctly cleans up empty blocks when selecting the next first block (#7384)
- The filestore now correctly obeys `sync_always` for writing TTL and scheduling state files (#7385)
- The filestore will now correctly expire a cache when the wrong sequence is found (#7396)
- Fixed a data race on a wait group when mirroring streams (#7395)
- Skipped message sequences are now checked for ordering before apply, fixing a potential stream desync on catchups (#7400)
- Skipped message sequences now correctly detect gaps from erased message slots, fixing potential cache issues, slow reads and issues with catchups (#7399, #7401)
- Raft groups now report peer activity more consistently, fixing some cases where asset info and monitoring endpoints may report misleading values after leader changes (#7402)
- Raft groups will no longer permit truncations from unexpected catchup entries if the catchup is completed (#7424)
- The filestore will now correctly release locks when erasing messages returns an error (#7431)

### Complete Changes
 
https://github.com/nats-io/nats-server/compare/v2.12.0...v2.12.1