* Fix filter combine logic for ChatHistoryMemoryProvider
* Replace var with explicit types in filter building code and test
Address PR review nit: use explicit types instead of var for better
readability in the filter-building logic and the new combined filter
compilation test.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* Fix style issues
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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>