Align desktop MCP onboarding and complete notarization gate

[trissim]

Summary

• Keep the existing codex registration target as the single owner of the shared ~/.codex/config.toml, while correctly presenting that registration to both ChatGPT desktop and Codex.
• Update Windows and macOS installer UI, user documentation, installer documentation, website copy, and focused tests to match current local desktop versus ChatGPT web behavior.
• Retrieve the authoritative Apple notarization log for the exact accepted submission, emit it, and independently require its status to remain Accepted before stapling, validation, Gatekeeper assessment, or upload.
• Document that notarytool API-key authentication requires a team App Store Connect key.

No duplicate ChatGPT registration target or parallel client registry was added.

Current authorities

• OpenAI MCP documentation states that ChatGPT desktop, Codex CLI, and the IDE extension share MCP configuration and that ChatGPT desktop supports local STDIO servers.
• Apple notarization workflow requires reviewing the submission log even after success.
• Apple packaging guidance confirms inside-out signing, outermost-container notarization, stapling, and distributed-product testing.

Verification

• Combined installer, release, registration, and website suite: 90 passed
• Focused cross-platform onboarding suite: 55 passed
• Complete installer plus release-workflow gate: 56 passed
• Strict Sphinx dummy build: all 149 sources passed with -W --keep-going
• Ruff, Bash syntax, workflow YAML ordering, and diff hygiene: passed
• Windows installer source: parsed successfully with Microsoft PowerShell 7.5

A native credentialed Apple notarization was not claimed: the repository currently has no Apple signing/notary secrets, and public v0.6.4 remains unsigned.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[augmentcode]

^{PR Risk Analyzer Agent🛡️}

👀 Human Input Needed
A pair-review briefing is ready for you.

→ Pair Review Briefing

[augmentcode]

^{Deep Code Review Agent🐛}

Review completed with 0 suggestions.