test: cover sustained native output

[jacklv-coder]

Summary

• extend the native smoke with byte-exact 8 MiB binary stdout, crossing the 4 MiB native session backlog
• retain real stdout quota coverage by attempting another 64 KiB beyond the 8 MiB limit
• add a 64-byte stderr overflow immediately afterward, proving recovery from stdout termination, then verify recovery again
• update the bilingual evidence and roadmap to 16 checks while keeping peak memory and jetsam explicitly open

Validation

• full iOS 18.2 arm64 Simulator native smoke with pinned v0.3.3 RootFS — 16 checks passed
• swift test — 137 tests, 1 expected environment-gated skip, 0 failures
• strict-concurrency PocketRootIshRuntime build with warnings as errors
• pinned release-asset integration test
• bilingual docs/link validation and smoke-script regression
• Demo build and runtime Simulator/device compile spike
• Codex CR: initial P2 fixed by restoring native stdout-limit coverage; final P1/P2 = 0