[gmemmy]

Problem

CI evidence packs previously required both Android and iOS even when a scenario intentionally selected one platform. That forced honest iOS-only or Android-only evidence into an unsupported shape, while weakening the distinction between missing required proof and a platform that was never in scope.

This PR adds an explicit platform scope without allowing single-platform evidence to imply mobile or cross-platform completeness.

What changed

• Adds single-platform and cross-platform scope to current CI evidence packs.
• Requires exactly one declared platform for single-platform packs and exactly Android plus iOS for cross-platform packs.
• Carries scope through assembly, receipts, summaries, GitHub reviewer reports, schemas, exports, CLI output, and packed-consumer coverage.
• Keeps legacy 1.0.0 two-platform packs readable without rewriting their bytes.
• Treats undeclared platforms as out of scope and missing declared platforms as failures.

Why this approach

Platform scope belongs to the evidence claim, not the runner or product scenario. Live-proof-set remains a platform inventory; the CI pack declares what coverage it claims. This preserves exact legacy behavior while making current single-platform claims explicit and fail closed.

Proof

Controller checks:

• pnpm typecheck - passed.
• pnpm exec tsc -p tsconfig.json - passed.
• Focused CI evidence suite - 249 tests passed.
• pnpm package:smoke - passed, including installed-package CLI, receipt, summary, GitHub report, and legacy-reader rehearsal.
• pnpm release:check - passed at exact reviewed SHA 951579a318853c23f6474329acc82b8fc9ef004a; 1,871 tests passed, release readiness passed, package smoke passed, and installed-consumer rehearsal passed.
• git diff --check - passed.

Independent review:

• Initial remediation review found one test-isolation issue.
• The test was corrected to add one explicit out-of-scope Android publication claim to valid iOS-only facts and assert the exact rejection reason.
• Final independent re-review of 951579a318853c23f6474329acc82b8fc9ef004a was CLEAN with no P0-P3 findings.

Runtime proof: Not run. This PR proves package and fixture behavior, not device execution or product acceptance.

Release proof: Not performed. A green release harness is not npm publication, a tag, or a GitHub Release.

Risks and limits

• Single-platform evidence proves only the declared platform.
• Product verdict, runtime acceptance, comparison, release, deployment, and merge acceptance remain separate.
• Android-only packed rehearsal is deferred; the shared contract and assembler have focused Android-only coverage.
• This PR does not change live-proof-set schema version or remove the deprecated legacy derivation export.

Stack/review order

1. #342 - portable promoted evidence packages.
2. #343 - idempotent profile-session stop.
3. This PR - explicit CI evidence platform scope.

Review and merge bottom-up. This PR is based on #343.

Follow-ups

• Complete generated scaffold helper coverage.
• Harden crash-safe evidence publication and duplicate semantic pointer verification.
• Cut and validate a new immutable package candidate only after the full release-correction train is green.