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

docs/specs/claude-code.md

@@ -0,0 +1,67 @@
+# Claude Code Plugin Spec
+
+Last verified: 2026-01-21
+
+## Primary sources
+
+```
+https://docs.claude.com/en/docs/claude-code/plugins-reference
+https://docs.claude.com/en/docs/claude-code/hooks
+https://docs.claude.com/en/docs/claude-code/slash-commands
+https://docs.claude.com/en/docs/claude-code/skills
+https://docs.claude.com/en/docs/claude-code/plugin-marketplaces
+```
+
+## Plugin layout and file locations
+
+- A plugin root contains `.claude-plugin/plugin.json` and optional default directories like `commands/`, `agents/`, `skills/`, `hooks/`, plus `.mcp.json` and `.lsp.json` at the plugin root. citeturn2view7
+- The `.claude-plugin/` directory only holds the manifest; component directories (commands/agents/skills/hooks) must be at the plugin root, not inside `.claude-plugin/`. citeturn2view7
+- The reference table lists default locations and notes that `commands/` is the legacy home for skills; new skills should live under `skills/<name>/SKILL.md`. citeturn2view7
+
+## Manifest schema (`.claude-plugin/plugin.json`)
+
+- `name` is required and must be kebab-case with no spaces. citeturn2view8
+- Metadata fields include `version`, `description`, `author`, `homepage`, `repository`, `license`, and `keywords`. citeturn2view8
+- Component path fields include `commands`, `agents`, `skills`, `hooks`, `mcpServers`, `outputStyles`, and `lspServers`. These can be strings or arrays, or inline objects for hooks/MCP/LSP. citeturn2view8turn2view9
+- Custom paths supplement defaults; they do not replace them, and all paths must be relative to the plugin root and start with `./`. citeturn2view9
+
+## Commands (slash commands)
+
+- Command files are Markdown with frontmatter. Supported frontmatter includes `allowed-tools`, `argument-hint`, `description`, `model`, and `disable-model-invocation`, each with documented defaults. citeturn6search0
+
+## Skills (`skills/<name>/SKILL.md`)
+
+- Skills are directories containing `SKILL.md` (plus optional support files). Skills and commands are auto-discovered when the plugin is installed. citeturn2view7
+- Skills can be invoked with `/<skill-name>` and are stored in `~/.claude/skills` or `.claude/skills` (project-level); plugins can also ship skills. citeturn12view0
+- Skill frontmatter examples include `name`, `description`, and optional `allowed-tools`. citeturn12view0
+
+## Agents (`agents/*.md`)
+
+- Agents are markdown files with frontmatter such as `description` and `capabilities`, plus descriptive content for when to invoke the agent. citeturn2view7
+
+## Hooks (`hooks/hooks.json` or inline)
+
+- Hooks can be provided in `hooks/hooks.json` or inline via the manifest. Hooks are organized by event → matcher → hook list. citeturn2view7
+- Plugin hooks are merged with user and project hooks when the plugin is enabled, and matching hooks run in parallel. citeturn1search0
+- Supported events include `PreToolUse`, `PostToolUse`, `PostToolUseFailure`, `PermissionRequest`, `UserPromptSubmit`, `Notification`, `Stop`, `SubagentStart`, `SubagentStop`, `Setup`, `SessionStart`, `SessionEnd`, and `PreCompact`. citeturn2view7
+- Hook types include `command`, `prompt`, and `agent`. citeturn2view7
+- Hooks can use `${CLAUDE_PLUGIN_ROOT}` to reference plugin files. citeturn1search0
+
+## MCP servers
+
+- Plugins can define MCP servers in `.mcp.json` or inline under `mcpServers` in the manifest. Configuration includes `command`, `args`, `env`, and `cwd`. citeturn2view7turn2view10
+- Plugin MCP servers start automatically when enabled and appear as standard MCP tools. citeturn2view10
+
+## LSP servers
+
+- LSP servers can be defined in `.lsp.json` or inline in the manifest. Required fields include `command` and `extensionToLanguage`, with optional settings for transport, args, env, and timeouts. citeturn2view7turn2view10
+
+## Plugin caching and path limits
+
+- Claude Code copies plugin files into a cache directory instead of using them in place. Plugins cannot access paths outside the copied root (for example, `../shared-utils`). citeturn2view12
+- To access external files, use symlinks inside the plugin directory or restructure your marketplace so the plugin root contains shared files. citeturn2view12
+
+## Marketplace schema (`.claude-plugin/marketplace.json`)
+
+- A marketplace JSON file lists plugins and includes fields for marketplace metadata and a `plugins` array. citeturn8view2
+- Each plugin entry includes at least a `name` and `source` and can include additional manifest fields. citeturn8view2