Add UnlinkPool event metadata

[Th0rgal]

Summary

• bump Verity to bd211c574f45cda31d66feab1bbc7e9d08dc5486 for macro event declarations
• add event_defs metadata for the UnlinkPool interface events
• update the case manifest to record the new Verity pin and event metadata tag

Notes

• dynamic_array_event_payloads remains unsupported: the event declarations now carry ABI metadata, but the existing emit sites still use scalar surrogate counts until source-faithful dynamic array payload emission is available.

Checks

• lake build Benchmark.Cases.UnlinkXyz.Pool.Compile
• git diff --check

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Note

Low Risk
Low risk: changes are limited to adding event metadata declarations and bumping the pinned verity dependency, without altering contract execution logic.

Overview
Adds explicit event_defs for UnlinkPool (e.g. Deposited, Transferred, Withdrawn, relayer/router events) so event ABI metadata is captured in the macro-generated compilation model.

Bumps the pinned verity dependency to bd211c57… and updates the Unlink pool case manifest (case.yaml) to record the new version and tag (macro_event_declarations).

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