feat: ShiftDetailModal rework, Today cancellation events, shift details icon button

- Backend: add cancellation_events (row count) to _enrich_shift and shift summary
- Backend: add cancellation_events field to current business day endpoint
- Today tab: hero number now shows cancellation_events (distinct cancel actions),
  sub-label shows 'X παραγγελίες / Y είδη'
- ShiftsOverview: Λεπτομέρειες button is now icon-only (Eye, light blue) matching
  the delete button style
- ShiftDetailModal: modal widened to 1080px; ΠΑΡΑΔΟΘΗΚΑΝ KPI replaced with
  Ακυρώσεις showing 'X events / Y items'; all filter labels renamed (Πλήρης
  Παραγγελία, Μόνο Πληρώθηκε, Μόνο Παρήγγειλε, Ανοιχτό ακόμη); new Ακυρώθηκε
  filter added; cancelled items shown in red, Πληρώθηκε line hidden for cancelled;
  legend updated; classify() handles cancelled status before other checks

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

local_backend/routers/reports.py

@@ -1263,12 +1263,17 @@ def current_business_day(
     # Count cancelled items (individual items cancelled, across all orders in this day)
     all_order_ids = [o.id for o in orders]
     cancelled_items_qty = 0
+    cancellation_events = 0
     if all_order_ids:
         from sqlalchemy import func as sqlfunc
         cancelled_items_qty = db.query(sqlfunc.sum(OrderItem.quantity)).filter(
             OrderItem.order_id.in_(all_order_ids),
             OrderItem.status == "cancelled",
         ).scalar() or 0
+        cancellation_events = db.query(sqlfunc.count(OrderItem.id)).filter(
+            OrderItem.order_id.in_(all_order_ids),
+            OrderItem.status == "cancelled",
+        ).scalar() or 0
 
     return {
         "business_day": {
@@ -1283,6 +1288,7 @@ def current_business_day(
             "active_waiters": len(active_shifts),
             "cancellations": len(cancelled_orders),
             "cancelled_items": int(cancelled_items_qty),
+            "cancellation_events": int(cancellation_events),
             "top_product": top_product,
         }
     }