Documentation cleanup for public release (#123)

Prepares the docs for the public release announcement: removes obsolete/dead
material, fixes drift between the API reference and the actual routes, and
standardizes on the default GitHub Pages URL.

- Remove Vagrant entirely: delete Vagrantfile, docs/dev_setup.md, and stale
  vagrant references in .gitignore/.dockerignore; rewrite openresty/README.md
  to describe the actual (currently unused) directory and point to
  ops/nginx_conf/ for the real OpenResty config.
- Delete docs/Update 4.11.md (personal scratch changelog) and drop both its
  and dev_setup.md's references from docs/README.md's Legacy Documentation
  section.
- Remove checkmark emoji from docs/contributing.md's PR Requirements list.
- Bring the auth model docs up to date with the code: document
  GET /api/auth/oidc/start + /callback, the /api/permission and /api/group
  RBAC routers, the /api/dns/dynamic/* sub-API, and /api/api-token (self
  -service PATs) in both nodejs/api.md and docs/api.md; add the missing
  "Clear Host Cache" section; drop the invite-token/SSH-key endpoints that no
  longer exist in nodejs/routes/user.js; note admin-only routes. Mention
  OIDC/LDAP/RBAC as core features in README.md.
- Keep nodejs/api.md and docs/api.md fully in sync (same body, differing only
  in Jekyll front matter / relative links) instead of letting them drift.
- Fix Node.js version references (20.x -> 22.x) in README.md and
  docs/installation.md to match ops/install.sh and the Dockerfile.
- Note that the manual nginx-conf/systemd install steps in README.md and
  docs/installation.md won't auto-track repo changes the way install.sh's
  symlink approach does, and recommend install.sh.
- Update the stale test/unit file lists in docs/contributing.md and
  nodejs/test/README.md to match the actual directory contents.
- Add npm run test:integration to README.md's Running Tests section.
- Add nodejs/conf/, nodejs/controller/, and nodejs/migrations/ to the project
  structure diagrams in README.md, docs/architecture.md, and
  docs/contributing.md.
- Standardize "CloudFlare" -> "Cloudflare" everywhere to match the actual API
  value in nodejs/models/dns_provider.js.
- Add the missing app_auth__adminGroups row to DEPLOYMENT.md's app_* table.
- Delete docs/CNAME (custom domain) so GitHub Pages serves from the default
  https://theta42.github.io/proxy/, matching docs/README.md.

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

docs/architecture.md

@@ -42,7 +42,7 @@ The proxy system consists of three main components working together to provide h
                                     ▼
                           ┌──────────────────────┐
                           │    DNS Providers     │
-                          │  - CloudFlare        │
+                          │  - Cloudflare        │
                           │  - DigitalOcean      │
                           │  - PorkBun           │
                           │  (DNS-01 challenges) │
@@ -84,6 +84,9 @@ The proxy system consists of three main components working together to provide h
 ```
 nodejs/
 ├── bin/www              # Application entry point
+├── conf/                # Configuration (base.js, environment overlays, secrets.js)
+├── controller/          # App-level wiring (pubsub, startup)
+├── migrations/          # One-off Redis data migration scripts
 ├── models/              # Data models
 │   ├── host.js          # Host configuration and lookup
 │   ├── auth.js          # Authentication logic
@@ -93,7 +96,10 @@ nodejs/
 │   ├── host.js          # Host CRUD operations
 │   ├── dns.js           # DNS provider management
 │   ├── user.js          # User management
-│   └── auth.js          # Authentication
+│   ├── auth.js          # Authentication (login + OIDC)
+│   ├── permission.js    # RBAC permission management
+│   ├── group.js         # Local group management
+│   └── api_token.js     # Self-service API (PAT) tokens
 ├── services/            # Background services
 │   ├── host_lookup.js   # Unix socket server
 │   └── host_scheduler.js # Cert renewal scheduler