chore(workflow): add AI-assisted workflow commands and configurations

Add comprehensive workflow commands for AI-assisted development:
- Claude commands: analyze, clarify, plan
- Kilocode workflows: full feature development lifecycle
- Opencode commands: specification and implementation workflows
- Roo MCP configuration for tool integration

Update .gitignore to exclude .astro build cache directories.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/frontend/.env.example

@@ -0,0 +1,8 @@
+# Environment variables reference
+# - .env.local: Used by Astro dev (pnpm dev) - use PUBLIC_ prefix for client-side vars
+# - dev.vars: Used by Wrangler Pages dev (pnpm dev:pages)
+# - Production: Variables set via Cloudflare dashboard
+
+# Payload CMS API Configuration
+PUBLIC_PAYLOAD_CMS_URL=https://enchun-admin.anlstudio.cc
+PAYLOAD_CMS_API_KEY=your_api_key_here