Fix Codex marketplace installs missing skills and MCP configuration

[stbenjam]

Installing link@link-plugins from this repository's Codex marketplace reports success, but the installed plugin contains only the Claude and Codex manifest directories. The marketplace selects ./plugins/link, where skills, .mcp.json, and assets are symlinks to files at the repository root. Codex skips these symlinks when copying the plugin into its installation cache.

This surfaced while investigating skillsaw warnings about manifest paths resolving outside the plugin root.

Point the Codex marketplace at ./ so it packages the existing root skills, MCP configuration, and assets. Set the root Codex manifest version to 0.18.0, matching packages/cli/package.json, update the version sync script to maintain it, and remove the redundant nested Codex manifest.

Before and after: installs directly from GitHub

Tested with Codex CLI 0.153.4, using a separate temporary CODEX_HOME for each repository. These were fresh GitHub marketplace installs, not installs from a modified local checkout.

before_profile=$(mktemp -d)
CODEX_HOME="$before_profile" codex plugin marketplace add stripe/link-cli --ref main --json
CODEX_HOME="$before_profile" codex plugin add link@link-plugins --json

after_profile=$(mktemp -d)
CODEX_HOME="$after_profile" codex plugin marketplace add stbenjam/link-cli --ref main --json
CODEX_HOME="$after_profile" codex plugin add link@link-plugins --json

GitHub source	Installed version	Cached skills	Cached .mcp.json	Cached logo
stripe/link-cli, main	0.15.1	0	Missing	Missing
stbenjam/link-cli, main	0.18.0	3	Present	Present

Both plugin add commands exited successfully. Inspected the actual installed files under each profile's plugins/cache/link-plugins/link/<version>/. The fixed installation includes:

skills/create-payment-credential/SKILL.md
skills/financial-insights/SKILL.md
skills/link-cli/SKILL.md
.mcp.json
assets/link.svg

Also confirmed that the installed MCP configuration contains the link server and both manifest icon paths resolve to a file.

Additional validation

• Verified the version sync script updates a deliberately stale root Codex manifest to 0.18.0 without recreating the nested manifest, using a temporary copy.
• All four Codex packaging rules pass with skillsaw 0.20.0: codex-plugin-json-valid, codex-plugin-structure, codex-marketplace-json-valid, and codex-marketplace-registration.
• Full repository skillsaw run introduces no findings: errors decrease from 9 to 5 and warnings from 5 to 3. Existing Claude/Cursor and skill-content findings remain.
• node --check scripts/sync-skill-version.js and git diff --check pass.

Validation covers installation and packaged contents; authentication and payment operations were not exercised.