feat: add OpenAI plugin manifest and OpenAPI 3.1 specification

- ai-plugin.json for OpenAI plugin registry submission
- openapi.yaml (OpenAPI 3.1.0) documenting all REST endpoints:
  core server (health, menu, cartridges, invoke), GitHub API
  passthrough (14 endpoints), GitLab API passthrough (8 endpoints),
  cloud providers (Cloudflare, Vercel, Verpex), browser automation,
  communications (Gmail, Calendar), ML (HuggingFace), and research
- Full schema definitions for all request/response types
- Security schemes for GitHub, GitLab, and BoJ tokens

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

ai-plugin.json

@@ -0,0 +1,18 @@
+{
+  "schema_version": "v1",
+  "name_for_human": "Bundle of Joy Server",
+  "name_for_model": "boj_server",
+  "description_for_human": "Cartridge-based DevOps toolkit with 55 formally verified domain cartridges spanning database, cloud, git, Kubernetes, containers, observability, secrets, IaC, ML, browser automation, communications, and research.",
+  "description_for_model": "A cartridge-based MCP server exposing 55 DevOps domain cartridges via a unified REST API. Each cartridge has a formally verified Idris2 ABI, Zig FFI bridge, and V-lang adapter. Domains include: database (VeriSimDB, PostgreSQL, Redis, DuckDB, MongoDB, Neo4j, ClickHouse, Turso, Supabase, Neon, ArangoDB), cloud providers (AWS, GCP, Cloudflare, Vercel, Verpex, DigitalOcean, Hetzner, Fly.io, Railway, Render, Linode), git forges (GitHub, GitLab), Kubernetes, containers, observability, secrets/vault, IaC, ML/AI (HuggingFace), browser automation (Firefox), communications (Gmail, Calendar), queues, SSG, research (academic papers), and language tooling. Use boj_menu to discover available cartridges, boj_cartridge_info to inspect a cartridge, and boj_cartridge_invoke to call operations.",
+  "auth": {
+    "type": "none"
+  },
+  "api": {
+    "type": "openapi",
+    "url": "https://raw.githubusercontent.com/hyperpolymath/boj-server/main/openapi.yaml",
+    "is_user_authenticated": false
+  },
+  "logo_url": "https://raw.githubusercontent.com/hyperpolymath/boj-server/main/assets/logo.png",
+  "contact_email": "j.d.a.jewell@open.ac.uk",
+  "legal_info_url": "https://github.com/hyperpolymath/boj-server/blob/main/LICENSE"
+}