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/installation.md

@@ -16,7 +16,7 @@ wget -O - https://raw.githubusercontent.com/theta42/proxy/master/ops/install.sh
 ```
 
 This automated installer will:
-- Install Node.js 20.x
+- Install Node.js 22.x
 - Install OpenResty and required dependencies
 - Install and configure Redis
 - Set up SSL fallback certificates
@@ -27,6 +27,15 @@ This automated installer will:
 
 ## Manual Installation
 
+> **Recommended path:** `ops/install.sh` (above) is idempotent and safe to
+> re-run — it symlinks the OpenResty/systemd config from the repo checkout,
+> so future updates stay in sync automatically (`git pull` + re-run). The
+> manual steps below *copy* those same files instead of symlinking them, so
+> they will **not** auto-track later changes to `ops/nginx_conf/` or
+> `ops/proxy.service` — you'd need to re-copy them by hand after every
+> update. Prefer the manual path only if `install.sh` doesn't fit your
+> distribution.
+
 ### System Requirements
 
 - Modern Linux distribution (Ubuntu 20.04+, Debian 11+, or equivalent)
@@ -41,13 +50,13 @@ This automated installer will:
 apt install libpam0g-dev build-essential redis-server luarocks -y
 ```
 
-### Step 2: Install Node.js 20.x
+### Step 2: Install Node.js 22.x
 
 ```bash
 curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | \
   sudo gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg
 
-NODE_MAJOR=20
+NODE_MAJOR=22
 echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | \
   sudo tee /etc/apt/sources.list.d/nodesource.list
 
@@ -56,7 +65,7 @@ apt update && apt install nodejs -y
 
 Verify installation:
 ```bash
-node --version  # Should show v20.x.x
+node --version  # Should show v22.x.x
 npm --version
 ```