[Roxas2712]

Imported GBA Helping Hand has no native handler, so portable mods cannot support a partner's move through ordinary engine execution. Register effect 176 and apply the native 1.5 modifier to the shared calculated damage after the critical multiplier and before STAB/type rounding.

The current living partner receives support once per round. Singles, missing partners, repeated support and a helper already supported by its partner fail normally. Status interruption, Protect flags, owned PP and imported priority remain authoritative. Support persists through actions/residual collection, resets at next-turn planning and does not transfer to a replacement battler. Fixed damage and confusion self-damage remain unmodified; other generations ignore the state.

Dependencies: #196 plus the existing #178 GBA base-damage and #175 critical-order corrections. Those published changes are reused as prerequisite commits. Review the two new feature commits relative to 45f5b4e. The additional #121 effect adapter enables canonical public effect = "HELPING_HAND" writes automatically without changing generated bindings.

Validation:

• 5,322/5,322 focused checks across FireRed/Emerald: every helper flank, actual mod-selected attacks, public move/damage events, critical/noncritical hits, STAB, physical/special/spread moves, resistance/immunity, variation 85/100, fixed damage/confusion exclusions, refusal/repetition/replacement/lifetime, real priority queues, PP and non-GBA guards.
• Same API-3 consumer and shared fixture against unchanged read-only Gen1Recomp 535a5ec088c1ae1bf4d91dd3e35a56f64cf46d91: 28 isolated workers / 1,916 paired observations pass, including prior enemy choices, selectors, records, targets and Follow Me.
• Actual numeric example: level-30 Tackle, equal Attack/Defense, normal STAB and roll 100 produces 16 unassisted and 24 supported through both native executors.
• Negative control on the clean prerequisite fails 391 assertions in the initial FireRed matrix.
• Existing paired GBA base-damage and critical-order checks pass.
• Full local quick run: 86/95 engine suites versus 85/94 on the clean prerequisite. The exact Counter of all 25 inherited FAIL lines across nine suites matches; no new failures. SDK 3/3 and B30 pass.
• Intended native registry addition changes the fixture fingerprint from 128fc071ae7249cd to 032184f68094e9ca. Removing only that entry and invalidating the cache restores the old value.
• Additional composition with Map portable move effects and secondary chances to native handlers #121: 12/12 checks load a real API-3 mod, patch/read the canonical effect and execute a publicly selected right-flank enemy move with supported damage and owned PP.
• actionlint and git diff --check pass.

Sessions use equal stats and synthetic extractor-shaped move rows, not a fresh cartridge import. Dedicated set-damage/delayed executors (Spit Up, Beat Up, Future Sight/Doom Desire), their other existing semantic differences, full ability/held-item ordering, AI scoring, called/link moves and full gameplay/RNG parity remain separately auditable surfaces. Gen1 is a read-only reference; no Gen1 source change or publication is required. Hosted CI and combined-fork acceptance are reported separately.

Combined-fork acceptance: integrated into Roxas2712:codex/portability-testing, tested runtime bf67876. All 213/213 engine suites, 3/3 SDK suites and B30 pass with zero FAIL lines. The same 28-worker / 1,916-observation comparison passes on that clean runtime. The canonical-effect mod proof passes 12/12. Integration updates the previous missing-handler assertion and audits the intentional effect-section fingerprint change; all six other populated sections stay identical. Subsequent combined commits only record validation.

Hosted CI: all five workflows report action_required pending maintainer approval. The dedicated enemy-action contract workflow has zero executed jobs. These are separate from local acceptance.