feat: rewrite busylight as FastAPI web application with SQLite

Replace the standalone Python script + config.cfg with a full web
application featuring:
- FastAPI backend with REST API
- SQLite database (config, state, activity log separated)
- Bootstrap 5 web interface for configuration
- Pages: Dashboard, Users, Devices, Assignments, Color Rules, Settings, Log
- APScheduler background polling for Teams presence + AIDA status
- systemd service file for Linux deployment
- Migration script to import existing config.cfg data

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

templates/log.html

@@ -0,0 +1,68 @@
+{% extends "base.html" %}
+{% block title %}Protokoll - Busylight{% endblock %}
+
+{% block content %}
+<div class="d-flex justify-content-between align-items-center mb-4">
+    <h4 class="mb-0">Protokoll</h4>
+    <span class="text-muted" id="last-update"></span>
+</div>
+
+<div class="card">
+    <div class="card-body p-0">
+        <div class="table-responsive">
+            <table class="table table-hover log-table mb-0">
+                <thead>
+                    <tr>
+                        <th>Zeitpunkt</th>
+                        <th>Benutzer</th>
+                        <th>AIDA-Status</th>
+                        <th>Teams-Status</th>
+                        <th>WLED-URL</th>
+                        <th>Ergebnis</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    {% for log in logs %}
+                    <tr>
+                        <td class="text-nowrap">{{ log.timestamp }}</td>
+                        <td>{{ log.user_name }}</td>
+                        <td>
+                            <span class="badge {% if log.aida_status == 'anwesend' %}bg-success{% elif log.aida_status == 'abwesend' %}bg-secondary{% elif log.aida_status == 'homeoffice' %}bg-warning text-dark{% else %}bg-light text-dark{% endif %}">
+                                {{ log.aida_status or '-' }}
+                            </span>
+                        </td>
+                        <td>
+                            <span class="badge bg-info">{{ log.teams_status or '-' }}</span>
+                        </td>
+                        <td><small class="font-monospace">{{ log.wled_url }}</small></td>
+                        <td>
+                            {% if log.result and '200' in log.result %}
+                                <span class="text-success"><i class="bi bi-check-circle"></i> {{ log.result }}</span>
+                            {% else %}
+                                <span class="text-danger"><i class="bi bi-x-circle"></i> {{ log.result }}</span>
+                            {% endif %}
+                        </td>
+                    </tr>
+                    {% endfor %}
+
+                    {% if not logs %}
+                    <tr>
+                        <td colspan="6" class="text-center text-muted py-4">
+                            Noch keine Protokoll-Eintraege vorhanden.
+                        </td>
+                    </tr>
+                    {% endif %}
+                </tbody>
+            </table>
+        </div>
+    </div>
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script>
+    setTimeout(() => location.reload(), 15000);
+    document.getElementById('last-update').textContent =
+        'Aktualisiert: ' + new Date().toLocaleTimeString('de-DE');
+</script>
+{% endblock %}