feat(export): Ersteller im Export-Dialog manuell eingebbar

Der Export-Dialog hat ein neues optionales Feld "Ersteller". Ist es
gefuellt, wird dieser Name im Bericht als Ersteller verwendet; bleibt es
leer, gilt wie bisher die E-Mail des Lage-Erstellers.

- export_incident: optionaler Query-Parameter creator, hat Vorrang vor
  der E-Mail-Ableitung
- exportReport (api.js) haengt creator an die Export-URL
- submitExport (app.js) liest das neue Feld aus
- Eingabefeld im Export-Modal (dashboard.html)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/static/js/api.js

@@ -330,7 +330,7 @@ const API = {
     resetTutorialState() {
         return this._request('DELETE', '/tutorial/state');
     },
-    exportReport(id, format, scope, sections, includeBranding) {
+    exportReport(id, format, scope, sections, includeBranding, creator) {
         const token = localStorage.getItem('osint_token');
         let url = `${this.baseUrl}/incidents/${id}/export?format=${format}`;
         if (sections && sections.length > 0) {
@@ -341,6 +341,9 @@ const API = {
         if (includeBranding === false) {
             url += `&branding=off`;
         }
+        if (creator) {
+            url += `&creator=${encodeURIComponent(creator)}`;
+        }
         return fetch(url, {
             headers: { 'Authorization': `Bearer ${token}` },
         });

src/static/js/app.js

@@ -2639,6 +2639,7 @@ async handleRefresh() {
         const format = document.querySelector('input[name="export-format"]:checked').value;
         const brandingEl = document.querySelector('input[name="export-branding"]:checked');
         const includeBranding = !brandingEl || brandingEl.value === 'on';
+        const ersteller = (document.getElementById('export-ersteller')?.value || '').trim();
 
         const btn = document.getElementById('export-submit-btn');
         const origText = btn.textContent;
@@ -2646,7 +2647,7 @@ async handleRefresh() {
         btn.textContent = (typeof T === 'function' ? T('action.creating', 'Wird erstellt...') : 'Wird erstellt...');
 
         try {
-            const response = await API.exportReport(this.currentIncidentId, format, null, sections, includeBranding);
+            const response = await API.exportReport(this.currentIncidentId, format, null, sections, includeBranding, ersteller);
             if (!response.ok) {
                 const err = await response.json().catch(() => ({}));
                 throw new Error(err.detail || 'Fehler ' + response.status);