Add Clear All Data feature to admin panel

- New 'Clear All Data' button on Overview page
- API endpoint to delete all submissions and tokens (keeps admin)
- Double confirmation to prevent accidents
- Resets settings to defaults

Useful for starting fresh sessions or testing

app/routes/admin.py

@@ -396,3 +396,26 @@ def import_data():
     except Exception as e:
         db.session.rollback()
         return jsonify({'success': False, 'error': str(e)}), 500
+
+@bp.route('/api/clear-all-data', methods=['POST'])
+@admin_required
+def clear_all_data():
+    """Clear all submissions and tokens (except admin)"""
+    try:
+        # Delete all submissions
+        Submission.query.delete()
+
+        # Delete all tokens except admin
+        Token.query.filter(Token.token != 'ADMIN123').delete()
+
+        # Optionally reset settings to defaults
+        Settings.set_setting('submission_open', 'true')
+        Settings.set_setting('token_generation_enabled', 'true')
+
+        db.session.commit()
+
+        return jsonify({'success': True, 'message': 'All data cleared successfully'})
+
+    except Exception as e:
+        db.session.rollback()
+        return jsonify({'success': False, 'error': str(e)}), 500

app/templates/admin/overview.html

@@ -92,6 +92,12 @@
                 <i class="bi bi-upload"></i> Import Session
             </button>
             <input type="file" id="importFile" accept=".json" style="display: none;" onchange="importData(this)">
+
+            {% if total_submissions > 0 or total_tokens > 0 %}
+            <button class="btn btn-danger" onclick="clearAllData()">
+                <i class="bi bi-trash-fill"></i> Clear All Data
+            </button>
+            {% endif %}
         </div>
 
         {% if total_submissions > 0 and unanalyzed_count > 0 %}
@@ -193,5 +199,40 @@ function importData(input) {
         input.value = '';
     });
 }
+
+function clearAllData() {
+    if (!confirm('⚠️ WARNING: This will permanently DELETE all submissions and tokens (except admin)!\n\nThis action CANNOT be undone.\n\nAre you absolutely sure?')) {
+        return;
+    }
+
+    if (!confirm('Last chance! Click OK to permanently delete all data.')) {
+        return;
+    }
+
+    const btn = event.target;
+    btn.disabled = true;
+    btn.innerHTML = '<i class="bi bi-hourglass-split"></i> Clearing...';
+
+    fetch('{{ url_for("admin.clear_all_data") }}', {
+        method: 'POST',
+        headers: {'Content-Type': 'application/json'}
+    })
+    .then(response => response.json())
+    .then(data => {
+        if (data.success) {
+            alert('✅ All data cleared successfully!');
+            location.reload();
+        } else {
+            alert('Error: ' + (data.error || 'Failed to clear data'));
+            btn.disabled = false;
+            btn.innerHTML = '<i class="bi bi-trash-fill"></i> Clear All Data';
+        }
+    })
+    .catch(error => {
+        alert('Error clearing data');
+        btn.disabled = false;
+        btn.innerHTML = '<i class="bi bi-trash-fill"></i> Clear All Data';
+    });
+}
 </script>
 {% endblock %}