Phase 1: Sidebar-Navigation, Dashboard-Cockpit & HTMX-Integration

- New sidebar layout (6 sections: Dashboard, Personen, Land, Finanzen, Dokumente, System)
- Collapsible sidebar with localStorage persistence
- Top bar with user dropdown and breadcrumbs
- Dashboard cockpit with live KPI cards (Destinataere, Foerderungen, Zahlungen, Laendereien)
- Action items: overdue Nachweise, pending payments, upcoming events, new emails, expiring leases
- Quick actions panel and recent audit log
- HTMX (2.0.4) and Alpine.js (3.14.8) integration via CDN
- django-htmx middleware and CSRF token setup
- Fix IMAP_PORT empty string handling in settings

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/core/settings.py

@@ -35,6 +35,7 @@ INSTALLED_APPS = [
     "django.contrib.humanize",
     "rest_framework",
     "rest_framework.authtoken",
+    "django_htmx",
     "django_otp",
     "django_otp.plugins.otp_totp",
     "django_otp.plugins.otp_static",
@@ -48,6 +49,7 @@ MIDDLEWARE = [
     "django.middleware.security.SecurityMiddleware",
     "django.contrib.sessions.middleware.SessionMiddleware",
     "django.middleware.common.CommonMiddleware",
+    "django_htmx.middleware.HtmxMiddleware",
     "django.middleware.csrf.CsrfViewMiddleware",
     "django.contrib.auth.middleware.AuthenticationMiddleware",
     "django_otp.middleware.OTPMiddleware",
@@ -131,7 +133,7 @@ CELERY_BEAT_SCHEDULE = {
 # IMAP-Konfiguration für E-Mail-Eingang (Destinatäre)
 # Pflichtfelder: IMAP_HOST, IMAP_USER, IMAP_PASSWORD
 IMAP_HOST = os.getenv("IMAP_HOST", "")
-IMAP_PORT = int(os.getenv("IMAP_PORT", "993"))
+IMAP_PORT = int(os.getenv("IMAP_PORT") or "993")
 IMAP_USER = os.getenv("IMAP_USER", "paperless@vhtv-stiftung.de")
 IMAP_PASSWORD = os.getenv("IMAP_PASSWORD", "")
 IMAP_FOLDER = os.getenv("IMAP_FOLDER", "INBOX")