feat(frontend): workday summary modal, print analytics UI, staff zone-PIN management, report upgrades

manager_dashboard:
- DashboardPage: WorkdaySummaryModal integration (view / close-day flows); revenue chart upgrades
- WorkdaySummaryModal: new component — shows full shift/revenue summary before closing the day
- StaffTab: full rewrite — zone-assignment modal, reset-PIN modal, actions dropdown, richer staff card
- ProductsTab: digital-menu fields surfaced in product form
- PrintFontsTab: expanded font-size/weight controls per printer channel
- TablesConfigTab / TablesPage / tableColourStore: color picker and zone fields for tables
- FilterBar: unified filter component with date-range, printer, and category selectors
- CategoryPerformance / ProductPerformance / TableAnalytics: donut/bar charts,
  thermal+browser print modals, richer breakdown tables
- PrinterHistory: redesigned with per-printer drill-down and summary blocks
- TrafficAnalytics / WorkDaySummary / RevenueTrends / ShiftsOverview / StaffLeaderboard: polish pass
- tokens.js: design token updates

waiter_pwa:
- TableCard: show table color indicator from zone/colour config

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

waiter_pwa/src/components/TableCard.jsx

@@ -636,6 +636,11 @@ export default function TableCard({
     '4x3': Card4x3,
   }[density] || Card2x2
 
+  const reservation = table.upcoming_reservation ?? null
+  const reservedTime = reservation
+    ? new Date(reservation.reserved_for).toLocaleTimeString('el-GR', { hour: '2-digit', minute: '2-digit' })
+    : null
+
   return (
     <div style={{ position: 'relative', minWidth: 0, overflow: 'hidden' }}>
       <button
@@ -651,6 +656,21 @@ export default function TableCard({
       >
         <CardComponent {...cardProps} />
       </button>
+      {reservation && (
+        <div style={{
+          position: 'absolute', top: 6, left: 6, zIndex: 10,
+          pointerEvents: 'none',
+        }}>
+          <span style={{
+            display: 'inline-flex', alignItems: 'center', gap: 3,
+            background: '#4f46e5', color: '#e0e7ff',
+            fontSize: 9, fontWeight: 800, letterSpacing: 0.3,
+            borderRadius: 4, padding: '2px 6px',
+          }}>
+            🔒 {reservedTime}
+          </span>
+        </div>
+      )}
 
       {showTip && flags.length > 0 && (
         <div style={{