feat(updates): visual update indicators, progress feedback, settings pull

- Dashboard: update badge (orange) injected lazily into customer Status cell
  after table renders via GET /monitoring/customers/local-update-status
  (local-only Docker inspect, no Hub call on every page load)
- Customer detail Deployment tab: "Update Images" button with spinner,
  shows success/error inline without page reload
- Monitoring Update All: now synchronous + sequential (one customer at a
  time), shows live spinner + per-customer results table on completion
- Settings > Docker Images: "Pull from Docker Hub" button with spinner
  and inline status message
- /monitoring/customers/local-update-status: new lightweight endpoint
  (no network, pure local Docker inspect)
- /monitoring/customers/update-all: removed BackgroundTasks, now awaits
  each customer sequentially and returns detailed per-customer results

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

static/lang/en.json

@@ -89,7 +89,9 @@
     "thHealth": "Health",
     "thImage": "Image",
     "lastCheck": "Last check: {time}",
-    "openDashboard": "Open Dashboard"
+    "openDashboard": "Open Dashboard",
+    "updateImages": "Update Images",
+    "updateInProgress": "Updating containers — please wait…"
   },
   "customerModal": {
     "newCustomer": "New Customer",
@@ -173,6 +175,9 @@
     "dashboardImage": "Dashboard Image",
     "dashboardImagePlaceholder": "netbirdio/dashboard:latest",
     "saveImageSettings": "Save Image Settings",
+    "pullImagesTitle": "Pull Latest Images from Docker Hub",
+    "pullImagesHint": "Downloads the latest versions of all configured NetBird images. After pulling, use Monitoring to update customer containers.",
+    "pullImages": "Pull from Docker Hub",
     "brandingTitle": "Branding Settings",
     "companyName": "Company / Application Name",
     "companyNamePlaceholder": "NetBird MSP Appliance",
@@ -299,7 +304,11 @@
     "pullStarted": "Image pull started in background. Re-checking in 5 seconds…",
     "confirmUpdateAll": "Recreate containers for all customers that have outdated images? Running services will briefly restart.",
     "updateAllStarted": "Update started in background.",
-    "updateDone": "Customer containers updated."
+    "updateDone": "Customer containers updated.",
+    "updating": "Updating…",
+    "updateAllProgress": "Updating customer containers one by one — please wait…",
+    "pulling": "Pulling…",
+    "pullStartedShort": "Pull started in background."
   },
   "userModal": {
     "title": "New User",