feat: [SDK-5456] add starter prompts, dark-theme brand assets, and a fuller listing description

[sherwinski]

One Line Summary

Add a third starter prompt, dark-theme brand assets, and a fuller longDescription to the ChatGPT / Codex listing, and teach the bundle gate to check them.

Screenshot

Motivation

The ChatGPT / Codex directory builds the starter-prompt banner from interface.defaultPrompt. Each chip shows composerIcon and colors the label with brandColor. On the dark theme the navy logomark and #051B2C label are not readable (see the screenshot in SDK-5456). The team also asked for a listing description with the same structure as Canva's: what the product is, what the plugin does, example prompts, and requirements.

Parent ticket: SDK-5455.

Scope

• .codex-plugin/plugin.json
  • defaultPrompt: 3 entries (setup, upload credentials, send a test push).
  • brandColorDark: "#4E50D1", the brand purple from the design team's OneSignal Logos/Purple folder. Contrast 2.60:1 against #212121 (the rule is 2:1).
  • logoDark and composerIconDark: ./assets/logomark-white.svg.
  • longDescription: 2,722 characters (limit 4,000), with line breaks. Every claim comes from README.md, the 3 SKILL.md descriptions, or references/platform-matrix.md.
• assets/logomark-white.svg: the official OneSignal-Logomark-White.svg, identical bytes to the public Media Kit and the Drive copy.
• scripts/package_directory_bundle.py: the gate checks logoDark and composerIconDark when set (source tree and built bundle), rejects interface.screenshots (a Skills-only upload refuses it), and has 2 new self-test cases.
• AGENT.md: one sentence in the bundle section updated to match.

Not in scope: a version bump. main is at 1.1.1 and the last tag is 1.1.0, so the tree already has an unreleased bump.

Not changed: the backdrop behind the chips. The ChatGPT client draws one static image (/cdn/assets/gradient.*.png) for every plugin; no manifest field supplies it.

Testing

Manual:

• python3 -m py_compile scripts/*.py: passed.
• python3 -m json.tool on the 4 JSON files: passed.
• Portability grep over skills/ and references/: no output.
• python3 scripts/package_directory_bundle.py --check: passed (version 1.1.1).
• python3 scripts/package_directory_bundle.py --self-test: all 12 cases rejected as expected, including the 2 new ones.
• python3 scripts/package_directory_bundle.py --out /tmp/os-bundle: the bundle has both assets, no mcpServers, 3 prompts, and the dark fields.

Not tested: a Skills-only upload of the new bundle to the OpenAI portal. That happens at the next release. The Codex desktop app renders this tree through the local onesignal marketplace; whether it renders an SVG composerIconDark is not confirmed yet.

Affected code

• Skills (skills/)
• References (references/)
• Scripts (scripts/)
• Manifests (.codex-plugin/, .claude-plugin/)
• Brand assets (assets/)
• Docs (AGENT.md)

Checklist

• The bundle gate (--check and --self-test) passes.
• No secrets in the diff.
• Commit messages use conventional prefixes and the ticket ID.

[kalley]

Dark assets and the gate checks look good, and the self-tests match what the gate prints. One non-blocking note inline. The description is a bit behind the later commits: longDescription is 815 characters now, not 2,722, and Scope doesn't mention the skill description rewrites.

[abdulraqeeb33]

Looks good. The dark asset and screenshots checks run on both the source tree and the built bundle, and the bundle checks pass with #61 stacked on top. Nothing to add beyond Kalley's notes.