feat: add location_slots to job_reservations for full slot persistence and update version to 0.9.1

Fix: modems do not show as "missing" any more, cleans up the dashboard.

templates/dashboard.html

@@ -509,7 +509,7 @@ function renderFilteredDashboard(data) {
 // Update the Recent Alerts section with filtering
 function updateAlertsFiltered(filteredActive) {
     const alertsList = document.getElementById('alerts-list');
-    const missingUnits = Object.entries(filteredActive).filter(([_, u]) => u.status === 'Missing');
+    const missingUnits = Object.entries(filteredActive).filter(([_, u]) => u.status === 'Missing' && u.device_type !== 'modem');
 
     if (!missingUnits.length) {
         // Check if this is because of filters or genuinely no alerts