v2.14.6

## Changelog

Refer to the [2.14 Upgrade Guide](https://docs.nats.io/release-notes/whats_new/whats_new_214) for backwards compatibility notes with 2.12.x. Please note that the 2.13.x version was skipped.

### Go Version

- 1.26.7

### Improved

General

- Removal from service import response maps is now constant-time (#8463)
- The client code no longer resets the deadline more times than necessary when flushing client buffers (#8513)
- The client write buffers are now freed correctly when the working buffer exceeds a rational size (#8515)

JetStream

- Stream reads are now isolated with a separate lock, which improves the performance of direct gets (#8486)
- Improved the performance of looking up matching sequence numbers for multi-subject gets (#8486)
- Reduced the number of heap escapes in subject tree matching (#8526)

### Fixed

General

- WebSocket client buffers are recycled more aggressively when reallocating into larger buffers (#8518)
- Fixed missing routes after a reconnect when gossiped URLs were rejected (#8527)

JetStream

- The filestore block sync no longer incorrectly skips blocks that were compacted during the same pass (#8456)
- The filestore block sync now performs a single directory sync upon completion rather than once per compacted block (#8461)
- The filestore I/O semaphore now covers block sync operations (#8462)
- Stream config updates with replicas greater than 1 are now rejected on non-clustered systems (#8464)
- Fixed some issues that could prevent stream snapshots from taking place on a clean shutdown (#8465)
- The filestore inline compaction no longer ignores `sync_interval: always` (#8475)
- The stream created time is now preserved after recovery on a standalone server (#8471, contributed by @Green7)
- Fixed a data race that could apply when accessing the batch ID (#8369)
- Fixed a data race when reading the consumer direct or sourcing status (#8478, contributed by @nberlee)
- Prevent the consumer direct or sourcing status from being changed with a consumer update (#8478, contributed by @nberlee)
- Fixed an issue where the server could fail to distinguish consumer tiers when enforcing limits (#8484)
- Fixed a flow control problem where replicated consumers could get stuck after a leader change (#8488)
- Fixed various consumer create issues that could destroy the state of an existing consumer with the same name (#8491)
- Internal message delete proposals are no longer counted in the JS API statistics (#8502)
- Dynamic filestore reservations no longer incorrectly shrink based on used storage after restarts (#8503)
- Fixed a signalling issue that could stall Raft catchups (#8501)
- The pending append entry cache in-memory is now bounded by size as well as entry count (#8501)
- Fixed an issue where a stale snapshot from a previous Raft group could be replayed if the group name was unchanged (#8501)
- Consumer delivery counts will no longer underflow below zero (#8512, contributed by @no-hup)
- `AckFlowControl` consumers from a work queue stream will no longer incorrectly ack messages outside of the consumer filter (#8431, #8528)

### Complete Changes
 
https://github.com/nats-io/nats-server/compare/v2.14.5...v2.14.6