[Roxas2712]

Add native playthrough-scoped records and opaque bytes for API 3, with a title-only storage:selected(game) facade. API-1/2 mods now also receive selected(game), delegated lazily to that same native service. Their existing installation-wide read/write/byte methods, paths and signatures remain unchanged; no automatic migration guesses which save owns an old shared payload.

The service provides detached context/data records, sorted keys, typed-key conflicts, verified staging/backup recovery and opaque identities allocated without gameplay RNG. Normal saves, legacy slot promotion, duplicate imports, failed writes and title/init ownership retain the existing identity contracts. The added legacy method creates its private delegate once, without changing the original storage namespace.

Depends on #154 and the preceding portability series. The original feature comparison remains 5ed6353...aef5650. The API-1/2 extension is isolated at 0740821, with the dependency-attribution correction at fefd080. Merge prerequisites first and rebase before integration. docs/api3-storage.md documents the base storage contract.

Validation:

• New actual-loader API-1/2 coverage: 20 checks for availability, exact native refusal codes, original record/byte behavior, unchanged root one-time delegate construction and calls from an active mod context without falsely requesting engine permissions. The delegate module is resolved during engine bootstrap.
• Updated public branch: 109/119 engine suites and 3/3 SDK suites. Fresh unchanged aef5650 parent: 108/118 engine suites. The exact 26 FAIL lines across the same ten inherited failing suites are identical; the new suite passes.
• Composed fork after the extension: gallery 253/253; 200 contract comparisons / 400 isolated loader runs against pinned 535a5ec088c1ae1bf4d91dd3e35a56f64cf46d91. The authenticated external package gate retains its explicitly named intermediate sprite-interface gap; complete acceptance is not claimed.
• Earlier base-service qualification at aef5650 remains applicable to the unchanged implementation: 1,013 native storage/lifecycle checks, 54 transaction assertions, 39 legacy-storage checks, 78 save-slot checks and 32 workers / 944 paired observations. Native LÖVE 11.5 prepare/restart/title/Continue checks were run in isolated Red, Gold, FireRed and Emerald profiles. These cover bounded persistence/startup, not full playthroughs.

FrameProfile before/after: not measured. This is an additive compatibility service; no performance switch applies. Hosted workflows require maintainer approval; local results above do not establish a new hosted pass.

Original additions by Roxas2712 are offered to Cedric / UNDERdecoded under the specific PR contribution permission at https://github.com/Roxas2712/Gen2Recomped/blob/4fb81fbf/LICENSE-ROXAS2712.md, with visible contributor credit. Existing rights, notices, credits and earlier permissions remain effective.

Current upstream qualification

Merged 8d5b4387; runtime 91f14c97 passes 120/120 engine suites and all SDK suites. The native supersample draw keeps the existing screen-visibility admission; both visibility suites also pass directly. This earlier standalone dependency host retains the inherited missing gallery files and lacks later contract/external-fixture runners; complete five-gate compatibility is qualified on the composed fork and P9 stack (#323). Existing repair commits #128–#134 and #294 are reused.