Fix AOF persistence and WATCH for collection-emptying RMW ops [dev]

[badrishc]

Bug 1: Collection-emptying RMW operations (LPOP, ZREM, HDEL, SREM that empty a collection) were not logged to AOF. InPlaceUpdaterWorker and PostCopyUpdater returned false before setting NeedAofLog when HasRemoveKey was true, so PostRMWOperation never wrote the AOF entry. Data reappeared after restart.

Bug 2: InPlaceUpdaterWorker's HasRemoveKey path did not call IncrementVersion on the watch version map, so WATCH/MULTI/EXEC transactions did not detect the key modification and incorrectly committed.

Bug 3: AofProcessor.RecoverReplay disposed respServerSession in its finally block, but in multi-DB recovery it ran once per database, causing double-dispose and NullReferenceException in GarnetLatencyMetricsSession.Return(). Moved dispose to AofProcessor.Dispose() which runs exactly once.

Fixes #1675

[Copilot]

Pull request overview

Fixes correctness issues around object-store RMW operations that empty collections, ensuring they are persisted to AOF and correctly tracked by WATCH, and addresses multi-DB AOF recovery double-dispose behavior.

Changes:

• Ensure collection-emptying object RMW mutations (e.g., LPOP/ZREM/HDEL/SREM that delete the key) set NeedAofLog so AOF replay preserves deletions.
• Increment WATCH version on the “remove key” path for in-place object updates so WATCH/MULTI/EXEC detects key modifications.
• Move AOF replay session disposal to AofProcessor.Dispose() to avoid double-dispose during multi-DB recovery; add regression tests for these scenarios.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/Garnet.test/TransactionTests.cs	Adds a WATCH regression test for list-emptying LPOP within a watched transaction flow.
test/Garnet.test/RespAofTests.cs	Adds AOF recovery tests covering object-store RMW deletes/partial deletes across lists, sets, hashes, and sorted sets.
test/Garnet.test/MultiDatabaseTests.cs	Adds multi-DB AOF recovery regression test for collection-emptying mutations across DBs.
libs/server/Storage/Functions/ObjectStore/RMWMethods.cs	Fixes AOF logging + WATCH version increments when RMW operations remove the key.
libs/server/AOF/AofProcessor.cs	Centralizes disposal in AofProcessor.Dispose() to avoid double-dispose across multi-DB recovery passes.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.