chore: release v1.19.6 - UI nav auth, SMTP UI-only, test messages, directory.md

### Fixed
- **Navbar shows Catalog/Vault for unauthenticated users** — Changed nav
  gating from `groups: []` (always visible) to `groups: ['login']` and
  added synthetic 'login' group handling in app-base.js.
- **500 ENOENT: no such file or directory, open '/docs/directory.md'** —
  Created the missing documentation file.

### Changed
- **SMTP configuration UI-only** — Removed SMTP from static config files
  (conf/base.js, sso-secrets.js, setup.env.example). SMTP is now only
  configurable via the runtime UI at /conf.

### Added
- **Test email/SMS capability** — Added POST /api/conf/test-email and
  POST /api/conf/test-sms endpoints with UI buttons in the Configuration
  page. Saves config first, then sends test message to verify settings.

### theta-env setup.sh
- **Non-interactive theta-agent configuration** — Added CFG_THETA_AGENT_ENABLE,
  CFG_THETA_AGENT_LDAP_AUTH, and CFG_THETA_AGENT_FULL_CONTROL variables to
  setup.env (all default to 1/enabled).

Co-Authored-By: Claude <noreply@anthropic.com>

nodejs/conf/base.js

@@ -57,14 +57,6 @@ module.exports = {
 		password: '__in secrets file__',
 		did:      '__in secrets file__',
 	},
-	smtp: {
-		host: 'localhost',
-		port: 587,
-		secure: false,
-		user: 'noreply@example.com',
-		pass: '__in secrets file__',
-		from: 'SSO Manager <noreply@example.com>',
-	},
 	directory: {
 		// Public SSH jump host fronting the lab, if there is one (the jump-host
 		// component). When set, a host card in the catalog shows the real