[POC] Prototype language-initiated Workflow cache eviction

[mjameswh]

Summary

• add maxWorkflowThreadHeapMiB and proactively evict least-recently-used idle Workflows under per-thread heap pressure
• expose Core's language-requested Workflow eviction through the bridge
• retain tombstones for locally disposed Workflows and send typed failed activation completions when activations race with local state loss
• replace failed or out-of-memory Workflow threads and request Core eviction for every Workflow they owned
• retain ordinary failed Workflow state until Core eviction, matching Retain failed Workflows until Core eviction #2378
• treat cleanup failure as fatal or replace the affected thread

Core dependency

Depends on temporalio/sdk-rust#1592 for the replay-state regression and clarified eviction contract. This branch points the sdk-core submodule at commit 5c958888d017225f4f8108f1b4eeafa519ff2009.

Testing

• TypeScript builds for @temporalio/worker and the test package
• 111 focused lifecycle, options, heap-policy, and Workflow tests
• changed-file ESLint
• Core targeted regression, lint, and formatting checks