Enable Codex to load EAPIL skills from a Git marketplace

Constraint: Codex marketplace sparse checkout expects .agents/plugins/marketplace.json under the selected marketplace root.\nRejected: Publish the raw skill/ directory | Codex plugin ingestion requires .codex-plugin/plugin.json and a plugin-local skills/ directory.\nConfidence: high\nScope-risk: narrow\nDirective: Keep plugins/codex as the sparse marketplace root unless Codex marketplace defaults change.\nTested: python json.tool; validate_plugin.py; codex plugin marketplace add .\\plugins\\codex --json; codex plugin add eapil-skills@eapil-skill-market --json; codex plugin list.\nNot-tested: Remote Git marketplace install after push.

README.md

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+# EAPIL Skill Market
+
+Codex custom plugin marketplace test repository.
+
+## Desktop test
+
+In **Add plugin marketplace**:
+
+- Source: `https://git.playones.com/arechen/EapilSkillMarket.git`
+- Git ref: `main`
+- Sparse path: `plugins/codex`
+
+After the marketplace is added, install `eapil-skills` from the `EAPIL Skill Market` marketplace.
+
+## CLI test
+
+```powershell
+codex plugin marketplace add https://git.playones.com/arechen/EapilSkillMarket.git --ref main --sparse plugins/codex
+codex plugin add eapil-skills@eapil-skill-market
+```
+
+For local testing before pushing:
+
+```powershell
+codex plugin marketplace add .\plugins\codex
+codex plugin add eapil-skills@eapil-skill-market
+```
+
+Start a new Codex thread after installing so the new skills are loaded into context.
+
+## Layout
+
+```text
+plugins/codex/
+  .agents/plugins/marketplace.json
+  plugins/eapil-skills/
+    .codex-plugin/plugin.json
+    skills/
+      pdf/
+      pptx/
+      xlsx/
+      threejs-animation/
+      threejs-fundamentals/
+      ...
+```