Add Today dashboard foundation with permission-aware KPI summary API.

Replace hardcoded Today cards with a backend summary endpoint and composable frontend widgets filtered by org type and tab permissions.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/scripts/build-messages.mjs

@@ -186,10 +186,20 @@ const en = {
     noSubscriptionNotice: 'This organization does not have an active subscription yet.',
     choosePlanLink: 'Choose a plan',
     noSubscriptionCta: 'to start the purchase process.',
-    cardTodaysAppointments: "Today's Appointments",
-    cardActivePatients: 'Active Patients',
-    cardNewLabCase: 'New Lab Case',
-    cardTodayInvoices: 'Today invoices',
+    noWidgets: 'No dashboard metrics are available for your current permissions.',
+    loadError: 'Could not load dashboard metrics.',
+    seatsUnlimited: 'Unlimited plan',
+    widgetAppointmentsToday: "Today's Appointments",
+    widgetPatientsToday: 'Patients Today',
+    widgetTreatmentsToday: 'Treatments Today',
+    widgetDraftTreatments: 'Draft Treatments',
+    widgetLabCasesPendingSend: 'Lab Cases Pending Send',
+    widgetCasesReceivedToday: 'Cases Received Today',
+    widgetTasksInProgress: 'Tasks In Progress',
+    widgetImportantTasks: 'Important Tasks',
+    widgetPendingConnections: 'Pending Connections',
+    widgetSeats: 'Seat Usage',
+    widgetPendingStaffInvites: 'Pending Staff Invites',
   },
   staff: {
     redirecting: 'Redirecting…',