Add Codex repository marketplace support

[ericjuta]

Summary

• add the repository marketplace descriptor and make the Ask Gina plugin root directly loadable by Codex/ChatGPT
• preserve lean generated host archives while moving the OpenAI manifest, MCP config, assets, and canonical skills to one source root
• add compiled, isolated Codex marketplace smoke coverage and CI execution against an immutable published revision
• integrate with the compiled ESM package layout from refactor: publish compiled ESM package artifacts #27 without reopening or duplicating that migration

Verification

• bun run audit — 320 packages, no vulnerabilities
• bun run check
• bun run effect-tsgo:diagnostics — 62 files, 0 diagnostics
• bun run test — 15 files, 133 tests
• bun run check:target-conformance — 192/192 checks
• bun run artifacts with Node 24.18.0
• bun run verify:artifacts with Node 24.18.0
• bun run check:public-boundary — 270 files, 11 archives, 0 findings
• bun run smoke:install with Node 24.18.0
• attested omp-reviewer --base origin/main — no findings (patch correct, 84% confidence)

Plan: #19, #23. Compiled ESM prerequisite: #27.

[ericjuta]

Delivered. Merge commit: e5f1deacaf388747741b427d48f8713183e57419.

Final evidence:

• branch and PR CI green at e2d468c17fdf2f5f9ff01a57ffd933fba24cd99c;
• main CI green at the merge commit: https://github.com/askgina/plugins/actions/runs/33016327886;
• main step Smoke Codex marketplace at published revision passed against that exact SHA;
• final public-boundary scan: 270 files, 11 archives, 0 findings;
• 15 test files / 133 tests; Effect TSGo 62 files / 0 diagnostics; audit 320 packages / 0 vulnerabilities;
• attested external review: no findings (patch correct, 78% confidence).

Repository visibility remains private. The clone token is exposed only to the trusted push smoke's marketplace add through an isolated askpass helper, and its token/helper files are removed before plugin installation. The delivery owner explicitly waived ChatGPT Desktop proof; this does not claim Desktop install, OAuth, or live tool execution.