chore: refresh automatic content (#711)

Author: mensfeld

Changelog/Karafka-Rdkafka.md

@@ -4,6 +4,7 @@
 # Rdkafka Changelog
 
 ## Unreleased
+- [Fix] Guard the message delivery callback so a raising user `delivery_callback` can no longer skip the handle unlock or crash the producer. `DeliveryCallback` invoked the user callback and only then unlocked the handle, with no rescue; if the callback raised, the handle stayed pending (so `wait` blocked until its timeout and raised `WaitTimeoutError` for a message that was actually delivered) and the exception unwound out of the FFI callback on librdkafka's polling thread (`abort_on_exception = true`), taking down the whole process. The user callback is now wrapped so exceptions are logged and swallowed (matching the rebalance callback) and the handle is always unlocked in an `ensure`.
 - [Enhancement] Extract the admin background-event result handlers into one class per operation under `lib/rdkafka/callbacks/` (`CreateTopicHandler`, `DescribeConfigsHandler`, etc., all subclasses of `Callbacks::BaseHandler`). `Callbacks::BackgroundEventCallback` is now a thin dispatcher that maps the event type to its handler and destroys the event. Purely internal reorganization (`Rdkafka::Callbacks` is private) with no behavior or API change.
 - [Enhancement] Expose `replicas` and `isrs` (in-sync replica broker ids) on each partition in topic metadata (`Metadata#topics` partition hashes). The base struct `#to_h` skips FFI pointer members, so these two arrays were dropped entirely and the partition replica assignment was unavailable to callers (e.g. for planning replication-factor changes). `PartitionMetadata#to_h` now dereferences both pointers into arrays of broker ids.
 - [Enhancement] Reuse per-thread scratch pointers in `Consumer::Headers.from_native` instead of allocating them for every consumed message. Previously each message paid one native pointer allocation just to check for headers and three more when headers were present; now the scratch pointers are allocated once per thread/fiber and reused, removing all per-message native scratch allocations from the consumer hot path.