feat(admin): DAU chart — events markers, week separators, weekend coloring

- Events shown as red 📅(N) above bars with attendee count
- Monday bars have dashed left border as week separator
- Weekend bars (Sat/Sun) in gray to distinguish from weekdays
- Hover tooltip shows event title and attendee count

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

blueprints/admin/routes_user_activity.py

@@ -169,6 +169,22 @@ def admin_user_activity():
             .all()
         )
 
+        # Events in this period (for chart markers)
+        from database import NordaEvent, EventAttendee
+        events_in_range = db.query(NordaEvent).filter(
+            NordaEvent.event_date >= start_date,
+            NordaEvent.event_date <= start_date + timedelta(days=30),
+        ).all()
+        event_map = {}  # date → {'title': ..., 'attendees': ...}
+        for ev in events_in_range:
+            att_count = db.query(func.count(EventAttendee.id)).filter(
+                EventAttendee.event_id == ev.id
+            ).scalar() or 0
+            event_map[ev.event_date] = {
+                'title': ev.title[:30] + ('...' if len(ev.title) > 30 else ''),
+                'attendees': att_count,
+            }
+
         # Fill in missing days with 0
         dau_map = {row.day: row.users for row in dau_q}
         daily_active = []
@@ -178,10 +194,16 @@ def admin_user_activity():
             count = dau_map.get(d, 0)
             if count > max_dau:
                 max_dau = count
+            is_weekend = d.weekday() >= 5  # 5=Saturday, 6=Sunday
+            is_monday = d.weekday() == 0
+            ev = event_map.get(d)
             daily_active.append({
                 'date': d,
                 'label': d.strftime('%d.%m'),
                 'count': count,
+                'is_weekend': is_weekend,
+                'is_monday': is_monday,
+                'event': ev,
             })
 
         # Add percentage for CSS bar heights

templates/admin/user_activity.html

@@ -152,6 +152,20 @@
         align-items: center;
         justify-content: flex-end;
         height: 100%;
+        position: relative;
+    }
+
+    .bar-col.weekend .bar {
+        background: linear-gradient(to top, #94a3b8, #b0bec5);
+    }
+    .bar-col.weekend .bar-label {
+        color: #94a3b8;
+    }
+
+    .bar-col.monday-start {
+        border-left: 1px dashed #cbd5e1;
+        margin-left: 2px;
+        padding-left: 2px;
     }
 
     .bar-value {
@@ -159,7 +173,18 @@
         font-weight: 600;
         color: var(--text-primary);
         line-height: 1;
-        margin-bottom: 4px;
+        margin-bottom: 2px;
+    }
+
+    .bar-event {
+        font-size: 8px;
+        color: #dc2626;
+        font-weight: 600;
+        line-height: 1;
+        margin-bottom: 2px;
+        white-space: nowrap;
+        max-width: 40px;
+        overflow: visible;
     }
 
     .bar-wrapper {
@@ -254,8 +279,11 @@
         <div class="chart-container">
             <div class="bar-chart">
                 {% for day in daily_active %}
-                <div class="bar-col" title="{{ day.label }}: {{ day.count }} użytkowników">
+                <div class="bar-col{{ ' weekend' if day.is_weekend }}{{ ' monday-start' if day.is_monday }}" title="{{ day.label }}: {{ day.count }} użytkowników{% if day.event %} | {{ day.event.title }} ({{ day.event.attendees }} zapisanych){% endif %}">
                     <span class="bar-value">{% if day.count > 0 %}{{ day.count }}{% endif %}</span>
+                    {% if day.event %}
+                    <span class="bar-event">📅({{ day.event.attendees }})</span>
+                    {% endif %}
                     <div class="bar-wrapper">
                         <div class="bar" style="height: {{ [day.pct, 5]|max if day.count > 0 else 0 }}%;"></div>
                     </div>