[macOS] Add macOS BAR.app runtime stack

[yeojuny]

Summary

This is a draft PR for the BAR.app macOS runtime stack in bar-lobby.

It adds the lobby-side pieces for launching the native macOS engine from the app bundle:

• macOS packaging/build configuration and BAR.app resources
• app-bundled native engine runner with bundled assets/runtime/MoltenVK/KosmicKrisp environment handling
• portable-state marker handling and macOS-specific content-source guardrails
• exact engine-version guard, Chobby/dev launch path, loopback/helper/profile handling
• Region/faction/start-script fixes needed by the app path
• focused unit coverage for runner, content source, updater, start script, preload bridge, and main lifecycle behavior
• clean-machine validation checklist for reproducing the BAR.app path on another Apple Silicon Mac

Why

The accepted Apple Silicon user path is BAR.app through bar-lobby. This PR makes the lobby own the native-engine handoff instead of relying on ad-hoc direct-engine scripts or local machine state.

Validation

Initial branch validation before rebasing onto the latest upstream master:

• git diff HEAD^..HEAD --check
• npm run typecheck:node
• npm run typecheck:web
• npx vitest run tests/unit/main/native-engine-runner.spec.ts tests/unit/main/content-sources.spec.ts tests/unit/main/auto-updater.spec.ts tests/unit/main/start-script-converter.spec.ts tests/unit/shared/preload-api-context-bridge.spec.ts

After rebasing onto upstream a444fb4:

• git diff origin/master...HEAD --check
• npm run typecheck:node
• npx vitest run tests/unit/main/native-engine-runner.spec.ts tests/unit/main/content-sources.spec.ts tests/unit/main/auto-updater.spec.ts tests/unit/main/start-script-converter.spec.ts tests/unit/shared/preload-api-context-bridge.spec.ts

After CI follow-up fixes on this head:

• git diff --check
• npx prettier --experimental-cli --check docs/macos-homebrew-runtime-packaging.md tests/unit/main/main-process-lifecycle.spec.ts
• npx prettier --experimental-cli --check src/main/config/native-engine-runner.ts tests/unit/main/native-engine-runner.spec.ts
• npx vitest run tests/unit/main/main-process-lifecycle.spec.ts
• npx vitest run tests/unit/main/native-engine-runner.spec.ts
• npm run typecheck:node
• npm run test (8 files, 58 tests)

Current npm run typecheck:web on the rebased branch reports an upstream-existing error in unchanged src/renderer/store/party.store.ts (PartyCreateOkResponseData.party vs partyId). This file has no diff in this PR.

Clean-machine path

See docs/macos-clean-machine-validation.md. The checklist defines the fresh-checkout build, bundled-assets input shape, static bundle checks, BAR.app runtime smoke signals, and failure ownership boundaries.

Related draft PRs

• Recoil runtime substrate: [macOS] Add macOS SDL3 EGL runtime substrate RecoilEngine#3060
• BAR content GS-free visual parity paths: [macOS] Add GS-free visual parity paths Beyond-All-Reason#8082

Notes for reviewers

This is draft because public distribution still needs clean-machine runtime closure, state scrubbing, signing/notarization/quarantine handling, and reproducible release packaging. Generated bundle files and local BAR-data state are intentionally not included.

[p2004a]

This PR will not be merged nor considered as presented and it doesn't make sense it stays open in the review queue.

1. It's way way too large and has too many independent changes
2. Is does it's own thing without any consideration how we want lobby to work, there is no design, for example We do not want any engine bundling.
3. It violates our AI policy