Prepare v0.1.1: downloadable macOS app and release workflow

[matyang-dev]

Codex Pulse currently requires users to install Xcode and build from source. This prepares a downloadable macOS preview with the local bridge and Node runtime included.

Changes:

• Universal macOS app, DMG/ZIP packaging and SHA-256 checksums; pinned official Node archives and bundled licenses.
• Explicit GUI bridge setup/repair/removal and opt-in radar controls; source installation retained, with ownership checks and rollback on setup failures.
• CP menu meter: C is 5-hour usage and P is weekly usage. Each shifts green → yellow → red over 0% → 50% → 100%; unavailable or cached values are gray.
• The legacy menu-bar utility no longer has a floating quota window or a show/hide-window menu action.
• Tagged GitHub Actions builds create draft prereleases only. Developer ID/notarization helper fails closed when prerequisites are missing.
• English/Chinese README download entry, first-launch guidance, real SwiftUI setup previews and v0.1.1 release notes.

Validation:

• 30 Node tests pass, including installer ownership/rollback, subprocess timeout/retry, privacy and bridge boundary tests.
• Native countdown/layout and EN/ZH setup renders pass; CP quota/color boundary mapping is covered.
• GitHub CI passed the complete macOS packaging flow, mounted-DMG and ZIP validation, and tests using the shipped Node runtime.

Limitations: companion app is unsandboxed for explicit per-user service setup; WidgetKit remains sandboxed. No signing secrets or account data are committed. Downloads are ad-hoc signed and unnotarized. Intel execution, clean-Mac Gatekeeper/widget registration and Apple notarization remain unverified. This is a prerelease.