fix: make Device Hub simulator launch opt-in

[thymikee]

Summary

Make standalone Simulator the default host app again when surfacing Apple simulators, and expose Xcode Device Hub only through the new --device-hub / deviceHub: true opt-in.

Device Hub surfacing for already-booted simulators uses non-activating open -g -a Device Hub, while cold-boot Device Hub launches still foreground normally.

Breaking change: this deliberately removes the --no-device-hub CLI flag and noDeviceHub client option that shipped in 0.17.2. That flag only existed to opt out of the Device-Hub-default behavior this PR reverts, so the default path now provides the same standalone Simulator behavior without a flag. Release notes for the next version should call out the removal for anyone who adopted it in 0.17.2.

Touched-file count: 19. Scope stayed within the open/simulator command surface and related tests/docs.

Validation

Verified with pnpm format, targeted unit tests for CLI parsing/client forwarding/device readiness/iOS simulator launch behavior, provider integration for tvOS simulator surfacing, pnpm check:fallow --base origin/main, and pnpm check:quick.

Additional cleanup after review replaced the overly broad internal activate?: boolean option with background?: boolean, wired only for the Device Hub already-booted path. A follow-up fallow cleanup simplified the simulator host provider predicate and branchy simulator launch test mocks.

The focused SkillGym case was added but not executed here because running external SkillGym runners from the sandbox was rejected by policy.

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-06-11 11:01 UTC

[github-actions]

Size Report

Metric	Base	Current	Diff
JS raw	1.2 MB	1.2 MB	-5.8 kB
JS gzip	392.0 kB	390.3 kB	-1.7 kB
npm tarball	510.2 kB	501.7 kB	-8.6 kB
npm unpacked	1.7 MB	1.7 MB	-35.1 kB

Startup median (7 runs, lower is better):

Scenario	Base	Current	Diff
CLI --version	27.2 ms	26.9 ms	-0.3 ms
CLI --help	42.1 ms	42.3 ms	+0.2 ms

Top changed chunks:

Chunk	Raw diff	Gzip diff
dist/src/2415.js	-5.8 kB	-1.7 kB
dist/src/8173.js	-40 B	-22 B
dist/src/1620.js	-103 B	-21 B
dist/src/1352.js	-48 B	-20 B
dist/src/session.js	-4 B	-1 B

[thymikee]

Fallow is blocking this PR on the latest run. The actionable findings are:

• test/integration/provider-scenarios/providers.ts:99 isSimulatorHostOpenCommand crossed the complexity gate.
• src/platforms/ios/__tests__/index.test.ts:415 and :556 test callbacks crossed the complexity gate.

Please split the branchy provider helper/test callbacks into small predicates or table-driven helpers, then rerun pnpm check:fallow --base origin/main. Other checks I saw were passing or still pending.

[thymikee]

Fixed in de58d84.

Changes:

• simplified the provider simulator-host open predicate from branchy conditionals to a command set lookup
• replaced the branch-heavy simulator launch test mocks with response-table helpers
• kept Device Hub opt-in behavior unchanged

Validation:

• pnpm check:fallow --base origin/main
• pnpm exec vitest run --project unit src/utils/tests/args.test.ts src/tests/client.test.ts src/daemon/tests/device-ready.test.ts src/platforms/ios/tests/index.test.ts
• pnpm exec vitest run --project provider-integration test/integration/provider-scenarios/tvos-remote.test.ts
• pnpm check:quick