Security hardening: env-based config, CSRF protection, secure code generation, plus presenter management and email communications system

- Move all credentials from hardcoded to .env with python-dotenv (add .env.example template and .gitignore)
- Add CSRF token generation and validation on all state-changing requests
- Replace random.choices with secrets.choice for all secure code generation
- Add session cookie security headers (HttpOnly, Secure, SameSite)
- Add presenter management: assign/remove presenters to breakout sessions, presenter QR scanning
- Add email communications system: templates per event, custom email sending, sent email tracking
- Add staff/organizer profile pages with staff code display
- New DB tables: event_email_templates, sent_emails, user_communications
- New DB columns: staff.reminder_count/reminder_dates, breakout_session_organizers.presenter_code
- Expand English translation strings across all new features

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

templates/organizer/badges.html

@@ -8,10 +8,10 @@
         <h1>{{ event.name }}</h1>
         <p>{{ 'attendee_badges'|t }}</p>
         <div class="header-actions">
-            <a href="{{ url_for('event_scan', event_id=event.id) }}" class="btn btn-secondary">📷 {{ 'scan_qr_codes'|t }}</a>
-            <a href="{{ url_for('download_rectangular_badges', event_id=event.id) }}" class="btn btn-secondary">🏷️ Rectangular Labels (80x50mm)</a>
-            <a href="{{ url_for('download_attendees_excel', event_id=event.id) }}" class="btn btn-secondary">📥 Download Excel</a>
-            <button onclick="window.print()" class="btn btn-primary">{{ 'print_badges'|t }}</button>
+            <a href="{{ url_for('event_scan', event_id=event.id) }}" class="btn btn-secondary"><i data-lucide="scan-line"></i> {{ 'scan_qr_codes'|t }}</a>
+            <a href="{{ url_for('download_rectangular_badges', event_id=event.id) }}" class="btn btn-secondary"><i data-lucide="tag"></i> Rectangular Labels (80x50mm)</a>
+            <a href="{{ url_for('download_attendees_excel', event_id=event.id) }}" class="btn btn-secondary"><i data-lucide="download"></i> Download Excel</a>
+            <button onclick="window.print()" class="btn btn-primary"><i data-lucide="printer"></i> {{ 'print_badges'|t }}</button>
         </div>
     </div>
 
@@ -37,7 +37,7 @@
                 <div class="badge-footer">
                     <span class="badge-id">#{{ attendee.id }}</span>
                     <span class="badge-check {% if attendee.checked_in %}checked-in{% endif %}">
-                        {% if attendee.checked_in %}✓ {{ 'checked_in'|t }}{% else %}{{ 'pending'|t }}{% endif %}
+                        {% if attendee.checked_in %}<i data-lucide="check"></i> {{ 'checked_in'|t }}{% else %}{{ 'pending'|t }}{% endif %}
                     </span>
                 </div>
                 <div class="badge-event-bar">
@@ -47,27 +47,6 @@
         {% endfor %}
     </div>
 
-    <style>
-    .badge-header h3 { margin: 0; font-size: 30pt; line-height: 1.1; }
-    .badge-header h3 .first-name,
-    .badge-header h3 .last-name { display: inline; line-height: 1.1; font-size: 30pt; }
-    .badge-header h3 .last-name:before { content: ' '; }
-@media print {
-    .navbar, .footer, .badges-header .header-actions button, .flash-messages { display: none !important; }
-    .badges-page { padding: 0; }
-    .badges-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
-    .badge-card { border: 2px solid #000; padding: 15px; page-break-inside: avoid; }
-    .badge-header h3 { margin: 0; font-size: 30pt; line-height: 1.1; }
-    .badge-header h3 .first-name,
-    .badge-header h3 .last-name { display: inline !important; line-height: 1.1; font-size: 30pt; }
-    .badge-header h3 .last-name:before { content: ' '; }
-    .badge-qr img { width: 80px !important; height: 80px !important; }
-    .badge-body p { margin: 5px 0; }
-    .badge-footer { display: flex; justify-content: space-between; margin-top: 10px; padding-top: 10px; border-top: 1px solid #ccc; }
-    .badge-event-bar { background: #000; color: #fff; padding: 8px 15px; margin: 10px -15px -15px; font-size: 12pt; text-align: center; }
-    .badge-event-bar { background: #000; color: #fff; padding: 8px 15px; margin: 10px -15px -15px; font-size: 12pt; text-align: center; }
-}
-    </style>
     <script>
     (function() {
         // Create offscreen canvas for text measurement