Initial commit: Notes Manager App (notes.braetter-int.de)

- Python/Flask Backend
- SQLAlchemy Models (notes, tasks, templates, users)
- Gunicorn + Nginx Deploy-Konfiguration
- Static Assets (CSS/JS)
- Jinja2 Templates

app/static/js/app.js

@@ -0,0 +1,14 @@
+document.addEventListener('DOMContentLoaded', () => {
+    const content = document.getElementById('content');
+    document.querySelectorAll('.template-btn').forEach(btn => {
+        btn.addEventListener('click', () => {
+            if (!content) return;
+            const tpl = btn.getAttribute('data-template');
+            if (content.value.trim() && !confirm('Vorhandenen Inhalt durch Vorlage ersetzen?')) {
+                return;
+            }
+            content.value = tpl;
+            content.focus();
+        });
+    });
+});