feat: Implement booking email notifications and consent handling in booking flow

Website/templates/schnell_buchung.html

@@ -112,6 +112,33 @@
         resize: vertical;
     }
 
+    .booking-review__consent {
+        padding: 0.95rem 1rem;
+        border-radius: 16px;
+        background: #eef6f6;
+        border: 1px solid #d2e2e2;
+    }
+
+    .booking-review__consent label {
+        display: flex;
+        gap: 0.7rem;
+        align-items: flex-start;
+        font-weight: 600;
+        color: #21414a;
+        line-height: 1.5;
+    }
+
+    .booking-review__consent input {
+        margin-top: 0.2rem;
+        width: auto;
+        flex: 0 0 auto;
+    }
+
+    .booking-review__consent a {
+        color: #0a4c74;
+        text-decoration: underline;
+    }
+
     .booking-review__actions {
         display: flex;
         flex-wrap: wrap;
@@ -202,6 +229,12 @@
                     <label for="notes">Zusatzinformationen</label>
                     <textarea id="notes" name="notes" maxlength="600" placeholder="Optional: gewünschter Starttermin, besondere Anforderungen, Rückrufzeiten">{{ form_data.notes }}</textarea>
                 </div>
+                <div class="booking-review__field booking-review__field--full booking-review__consent">
+                    <label for="agreements_accepted">
+                        <input id="agreements_accepted" name="agreements_accepted" type="checkbox" value="yes" required {% if form_data.agreements_accepted %}checked{% endif %}>
+                        <span>Ich habe die <a href="{{ url_for('nutzungsbedingungen') }}" target="_blank" rel="noopener">Lizenzvereinbarung</a>, die <a href="{{ url_for('datenschutz') }}" target="_blank" rel="noopener">Datenschutzerklärung</a> und die DSGVO-Hinweise gelesen und akzeptiere sie.</span>
+                    </label>
+                </div>
             </div>
 
             <div class="booking-review__actions">