[Roxas2712]

Beat Up's dedicated executor (#206) and native held-item adjustment (#182) need to reach the same build. Without #182, nonlethal, Substitute and Endure strikes can omit Focus Band draws, shifting later RNG and changing native execution.

Add cross-engine contract coverage through the same actual API-3 consumer, planner and native executor. FireRed and Emerald evaluate Focus Band independently for each reached strike; a previous successful roll must not save a later hit. This PR adds no new runtime behavior beyond its already published prerequisites.

Stacked on #206 plus #182. Clean composed prerequisite: 45220e4; review the test-only commit 03d68a4 against its parent. The #182 prerequisite cherry-pick preserves #206's Substitute clipping, per-strike counter memory and Spit Up Protect callback.

Validation:

• 1,672/1,672 focused checks: 17 cases at all four user positions on FireRed/Emerald, physical Focus Band 196 and imported-shaped item 1196, success/failure, strict chance boundary, zero-percent rolls, nonlethal/lethal hits, Substitute, Endure, later procs, callback removal/equipping and a second move. Verify owned PP, public hit metadata/amounts, counter memory, and exact number/order/value of Focus Band draws.
• Same real API-3 consumer/fixture against unchanged read-only Gen1Recomp 535a5ec088c1ae1bf4d91dd3e35a56f64cf46d91: 44 isolated workers / 4,622 paired observations pass. Clean combined runtime 4d16999 also passes this comparison.
• Negative control: Calculate native GBA Beat Up damage per party member #206 without Align native GBA AI held-item knowledge and observation producers #182 fails 56 assertions in the new FireRed cases. The clean composed prerequisite already has the correct behavior.
• Full local feature run: 90/99 engine suites versus 89/98 on the clean composed prerequisite. Exact Counters of all 25 inherited FAIL lines across nine suites match, with no additions. SDK 3/3 and B30 pass.
• Pinned JIT-enabled LuaJIT v2.1 a4c064539ea931274d407e1249b4bb575424a0f4; scoped StyLua, actionlint and git diff --check pass.
• Test-only coverage does not change built-in record revisions or fingerprint goldens.

The reference has a distinct move-local persistence policy for Ruby/Sapphire. FireRed/Emerald do not select it, so these tests do not invent that behavior. Native physical item IDs have built-in metadata; parameter mutation therefore uses an imported-shaped custom item rather than pretending to override that table.

Focus Band draws are checked at the actual 0..99 boundary; critical/variation observations retain the existing semantic normalization. Full raw RNG traces, other scripted executors, multi-trainer/link and Ruby/Sapphire controllers, animation and complete gameplay remain separate acceptance surfaces. Gen1 stays read-only, with no source changes or publication.

Combined full-suite acceptance and hosted CI are reported below.

Hosted CI: all six workflows for 03d68a4 report action_required pending maintainer approval. The dedicated contract run has zero executed jobs. Local acceptance is separate.

Combined-fork acceptance: integrated into Roxas2712:codex/portability-testing. Clean runtime 4d16999 passes 216/216 engine suites, 3/3 SDK suites and B30 with zero FAIL lines. The same runtime passes all 44 workers / 4,622 paired observations. The feature's only added runtime commit is its explicitly identified #182 prerequisite; the contract commit changes tests/workflow/docs only. Subsequent combined commits record validation.