feat(calendar): Add image support for events

Add image_url column to NordaEvent model with migration 066.
Display event banner image above description in event detail page.
Include converted WebP image for Lean breakfast event (2026-02-20).

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

database.py

@@ -2093,6 +2093,9 @@ class NordaEvent(Base):
     # Kontrola dostępu
     access_level = Column(String(50), default='members_only')  # public, members_only, rada_only
 
+    # Media
+    image_url = Column(String(1000))  # Banner/header image URL
+
     # Relationships
     speaker_company = relationship('Company')
     creator = relationship('User', foreign_keys=[created_by])

database/migrations/066_event_image_url.sql

@@ -0,0 +1,4 @@
+-- Migration 066: Add image_url column to norda_events
+-- Allows events to have a banner/header image
+
+ALTER TABLE norda_events ADD COLUMN IF NOT EXISTS image_url VARCHAR(1000);

templates/calendar/event.html

@@ -247,6 +247,12 @@
         {% endif %}
     </div>
 
+    {% if event.image_url %}
+    <div style="margin-bottom: var(--spacing-xl); border-radius: var(--radius-lg); overflow: hidden;">
+        <img src="{{ event.image_url }}" alt="{{ event.title }}" style="width: 100%; height: auto; display: block;">
+    </div>
+    {% endif %}
+
     {% if event.description %}
     <div class="event-description">
         {{ event.description|safe }}