Generalize email system with invoice workflow and Stiftungsgeschichte category

- Rename DestinataerEmailEingang → EmailEingang with category support
  (destinataer, rechnung, land_pacht, stiftungsgeschichte, allgemein)
- Add invoice capture workflow: create Verwaltungskosten from email,
  link DMS documents as invoice attachments, track payment status
- Add Stiftungsgeschichte email category with auto-detection patterns
  (Ahnenforschung, Genealogie, Chronik, etc.) and DMS integration
- Update poll_emails task with category detection and DMS context mapping
- Show available history documents in Geschichte editor sidebar
- Consolidate DMS views, remove legacy dokument templates
- Update all detail/form templates for DMS document linking
- Add deploy.sh script and streamline compose.yml

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

app/templates/base.html

@@ -657,11 +657,7 @@
             <div class="sidebar-heading">Dokumente</div>
             <a class="sidebar-link" href="{% url 'stiftung:dms_list' %}">
                 <i class="fas fa-folder-open"></i>
-                <span>DMS</span>
-            </a>
-            <a class="sidebar-link" href="{% url 'stiftung:dokument_management' %}">
-                <i class="fas fa-archive"></i>
-                <span>Paperless (Legacy)</span>
+                <span>Dokumente</span>
             </a>
         </div>