release(v2.2.0): 223 skills, security suite, self-eval, full docs update

- Add 8 new skills: 6 security (adversarial-reviewer, ai-security, cloud-security, incident-response, red-team, threat-detection), self-eval, snowflake-development
- Update all counts: 223 skills, 298 tools, 416 references, 23 agents, 22 commands
- Update CHANGELOG.md with v2.2.0 entry
- Update all plugin.json versions to 2.2.0
- Update CLAUDE.md, README.md, docs/index.md, docs/getting-started.md, mkdocs.yml
- Verify MkDocs build (301 pages), Codex/Gemini sync, all new scripts pass --help

https://claude.ai/code/session_011CHSDjqWBPRcEJ3oJrAUHS

engineering/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "engineering-advanced-skills",
-  "description": "36 advanced engineering skills: agent designer, agent workflow designer, AgentHub, RAG architect, database designer, migration architect, observability designer, dependency auditor, release manager, API reviewer, CI/CD pipeline builder, MCP server builder, skill security auditor, performance profiler, Helm chart builder, Terraform patterns, focused-fix, browser-automation, spec-driven-workflow, secrets-vault-manager, sql-database-assistant, and more. Agent skill and plugin for Claude Code, Codex, Gemini CLI, Cursor, OpenClaw.",
-  "version": "2.1.2",
+  "description": "36 advanced engineering skills: agent designer, agent workflow designer, AgentHub, RAG architect, database designer, migration architect, observability designer, dependency auditor, release manager, API reviewer, CI/CD pipeline builder, MCP server builder, skill security auditor, performance profiler, Helm chart builder, Terraform patterns, focused-fix, browser-automation, spec-driven-workflow, secrets-vault-manager, sql-database-assistant, self-eval, and more. Agent skill and plugin for Claude Code, Codex, Gemini CLI, Cursor, OpenClaw.",
+  "version": "2.2.0",
   "author": {
     "name": "Alireza Rezvani",
     "url": "https://alirezarezvani.com"