feat(lowering): materialize global rule array locals

[Teakowa]

Summary

• extend deterministic global-rule local storage to nested arrays of scalar WIR values
• lower local array literals, references, indexes, and assignments through canonical WIR
• allow the existing global foreach slice to read a materialized local array collection
• preserve fail-closed HI018 for player-context, object/reference, and re-entrant storage

Review order

This slice is stacked on PR #44 (agent/del-rs-31-foreach-20260818). Merge order is #41, #43, #44, then this PR.

Evidence

• cargo test --locked --test workshop_lowering -- --nocapture: 20 passed
• cargo test --locked --all-targets: passed
• cargo test --locked --test matrix --test corpus: 5 passed
• cargo run --locked --quiet -- matrix --check: 128 entries valid
• focused positive tests assert exact local-initialization → collection-materialization → index-initialization → while order, canonical WIR Array/GlobalVariable/valueInArray forms, generated helper names, and provenance
• focused negative tests cover player-context, object/reference elements, unsupported vector arrays, and non-reentrant bodies with structured HI018
• git diff --check and task-file rustfmt checks pass

Boundaries

• no parser, semantic-model, or typed HIR changes
• no provider-local Workshop catalog or WIR additions
• no object identity, reference generations, member layout, parameters, recursion stack, or closure ABI
• this is DEL adapter/WIR evidence, not live Overwatch-client execution evidence

Refs #31

[Teakowa]

Superseded by replacement PR #56, rebuilt from current main after #41/#54/#55. The old stacked implementation carried obsolete storage and validation assumptions; it is closed in favor of the current bounded array-local contract.

[Teakowa]

Closed as superseded by #56.