Allow array values in executable emit calls

[Th0rgal]

Summary

• add Contracts.EventArg so executable emit calls can accept scalar words and array values in one argument list
• coerce array event arguments to dynamic-array length placeholders for the executable event trace
• add macro smoke coverage for scalar plus array event emits and memory-array event emits

Verification

• git diff --check
• lake build Compiler.CompilationModelFeatureTest
• lake build PrintAxioms
• python3 scripts/generate_print_axioms.py --check
• python3 scripts/check_axioms.py

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Note

Medium Risk
Changes the Contracts.emit API and its coercions, which could subtly affect executable event traces for existing contracts, especially around dynamic array arguments. The change is conceptually small but touches a commonly used surface in contract stubs/tests.

Overview
Extends executable event emission to accept a mixed argument list of scalar words and dynamic arrays by introducing Contracts.EventArg and updating emit to map arrays to a dynamic-array length placeholder in the event trace.

Adds macro smoke coverage for emitting events with array parameters, including emitting an allocated memory array, and updates event-metadata assertions to cover the new array-typed events.

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