Rebuild OMSORG Connect from scratch: login-only milestone

New omsorgWeb/mitarbeiter-app/ replaces the legacy PHP app for now
with just the login flow, built fresh instead of incrementally
refactored. Reuses the already-working omsorgCore JWT auth pattern
(login, silent refresh, session-stored token pair, /api/auth/me for
role+permissions) but drops everything legacy carried alongside it:
no local MySQL user cache, no admin/user-management endpoints, no
admin UI. Employee/user management stays exclusive to OMSORG Desktop
per architecture decision - Connect only ever acts on the current
user's own session.

logout.php additionally revokes the refresh token server-side via
omsorgcore_logout(), which the legacy version never did.

Verified end-to-end against a running omsorgCore instance: login,
dashboard via /api/auth/me, logout + token revocation, unauth
redirect, and wrong-credential error handling.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

omsorgWeb/mitarbeiter-app/lib/config.secret.example.php

@@ -0,0 +1,7 @@
+<?php
+// Vorlage: nach config.secret.php kopieren und mit echten Werten füllen.
+// config.secret.php niemals ins Repo/Backup geben.
+return [
+    // Produktiv auf die echte omsorgCore-URL überschreiben (Default in config.php ist localhost, nur für lokale Entwicklung):
+    // 'omsorg_core_url' => 'https://core.omsorg-pflegedienste.de',
+];