Add self-service API tokens (PATs) with UI + Bearer auth (#35)

Personal access tokens so scripts/CI can call the management API without a
browser session. Each logged-in user mints their own token; it authenticates as
the creator (carries their LDAP group permissions, re-resolved live), so the
existing permission.byGroup checks apply unchanged.

- models/api_token.js: new ApiToken model (sso_<id>_<secret> format; id is the
  lookup key, secret bcrypt-hashed + isPrivate, shown once). add()/rotate()/
  authenticate(); optional expires_at; best-effort last_used_on. No _ttl
  (persists; lifetime via expires_at).
- routes/api_token.js: self-service CRUD (list/get/update/delete/rotate),
  owner-scoped (created_by === req.user.uid, 403 otherwise).
- middleware/auth.js + models/auth.js: accept `Authorization: Bearer sso_...`
  (precedence over the auth-token session header); checkApiToken collapses
  every failure to one generic 401 (no existence/secret/expiry leak).
- views/api_tokens.ejs + routes/index.js (GET /api-tokens): self-service page
  (forceLogin, no group gate) — create (token shown once), edit, rotate, revoke.
- views/top.ejs: "API Tokens" nav entry visible to all logged-in users.
- public/js/app.js: app.apiToken client module.
- DEPLOYMENT.md + docs/deployment.md: API tokens section.

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

nodejs/models/auth.js

@@ -2,6 +2,7 @@
 
 const {User} = require('./user');
 const {Token, AuthToken} = require('./token');
+const {ApiToken} = require('./api_token');
 
 var Auth = {}
 Auth.errors = {}
@@ -40,6 +41,20 @@ Auth.checkToken = async function(data){
 	}
 };
 
+// Validate an `Authorization: Bearer sso_<id>_<secret>` API token and return the
+// owning user (same shape as checkToken). Every failure collapses to the same
+// generic login 401 — no leak of whether the token existed vs. wrong secret vs.
+// expired. The token authenticates AS its creator; permissions are re-resolved
+// from LDAP live (permission.byGroup), so no groups snapshot is stored.
+Auth.checkApiToken = async function(raw){
+	try{
+		let token = await ApiToken.authenticate(raw);
+		return await User.get(token.created_by);
+	}catch(error){
+		throw this.errors.login();
+	}
+};
+
 Auth.logOut = async function(data){
 	try{
 		let token = await AuthToken.get(data);