[mcaxtr]

Keep pending legacy Queries in FIFO order and retain completion-returned and polled Workflow Tasks in separate bounded slots. This preserves each retained request's response token while Queries run before the next task advances workflow history.

Transfer the complete buffer through eviction and cache admission. While full history is fetched, retain later work for the same run and preserve the selected task's source if it must wait for cache capacity. Continue buffered work after a task's history fetch fails.

Worker regressions cover task replacement, Query ordering, eviction, delayed completion responses, history admission, cache capacity, response tokens and slot release. Both SDK audience changelogs describe the observable behavior.

Validation: 14 focused Worker tests; 1,062 workspace tests with experimental; cargo lint; cargo test-lint; 568 integration tests via cargo integ-test; nightly formatting and whitespace checks.

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[Sushisource]

Closing in favor of #1693 which is much simpler