feat: add OpenCode/Codex outputs and update changelog (#104)

* Add OpenCode converter coverage and specs

* Add Codex target support and spec docs

* Generate Codex command skills and refresh spec docs

* Add global Codex install path

* fix: harden plugin path loading and codex descriptions

* feat: ensure codex agents block on convert/install

* docs: clarify target branch usage for review

* chore: prep npm package metadata and release notes

* docs: mention opencode and codex in changelog

* docs: update CLI usage and remove stale todos

* feat: install from GitHub with global outputs

tests/fixtures/custom-paths/.claude-plugin/plugin.json

@@ -0,0 +1,8 @@
+{
+  "name": "custom-paths",
+  "version": "1.0.0",
+  "agents": "./custom-agents",
+  "commands": ["./custom-commands"],
+  "skills": "./custom-skills",
+  "hooks": "./custom-hooks/hooks.json"
+}