Add Codex superpowers integration

- Single unified script: superpowers-codex with bootstrap/use-skill/find-skills commands
- Cross-platform Node.js implementation (works on Windows, macOS, Linux)
- Namespaced skills: superpowers:skill-name for superpowers, skill-name for personal
- Personal skills override superpowers skills when names match
- Clean skill display: shows name/description without raw frontmatter
- Helpful context: shows supporting files directory for each skill
- Tool mapping for Codex: TodoWrite→update_plan, subagents→manual fallback, etc.
- Updated terminology: "Superpowers skills" instead of "Core skills"
- Bootstrap integration with AGENTS.md for automatic startup
- Installation guide and bootstrap instructions specific to Codex

codex/superpowers-bootstrap.md

@@ -0,0 +1,29 @@
+# Superpowers Bootstrap for Codex
+
+<EXTREMELY_IMPORTANT>
+You have superpowers.
+
+**Tool for running skills:**
+- `~/.codex/superpowers/scripts/superpowers-codex use-skill <skill-name>`
+
+**Tool Mapping for Codex:**
+When skills reference tools you don't have, substitute your equivalent tools:
+- `TodoWrite` → `update_plan` (your planning/task tracking tool)
+- `Task` tool with subagents → Tell the user that subagents aren't available in Codex yet and you'll do the work the subagent would do
+- `Skill` tool → `superpowers-codex use-skill` command (already available)
+- `Read`, `Write`, `Edit`, `Bash` → Use your native tools with similar functions
+
+**Skills naming:**
+- Superpowers skills: `superpowers:skill-name` (from ~/.codex/superpowers/skills/)
+- Personal skills: `skill-name` (from ~/.codex/skills/)
+- Personal skills override superpowers skills when names match
+
+**Critical Rules:**
+- Before ANY task, check the skills list shown below
+- If a relevant skill exists, you MUST use `superpowers-codex use-skill` to load it
+- Announce: "I've read the [Skill Name] skill and I'm using it to [purpose]"
+- Skills with checklists require `update_plan` todos for each item
+- NEVER skip mandatory workflows (brainstorming before coding, TDD, systematic debugging)
+
+IF A SKILL APPLIES TO YOUR TASK, YOU DO NOT HAVE A CHOICE. YOU MUST USE IT.
+</EXTREMELY_IMPORTANT>