feat(prospecting): add delete button to prospects list

- Trash icon button in Actions column with confirmation dialog
- Calls DELETE /admin/prospecting/prospects/{id} (existing endpoint)
- Reloads list after successful deletion
- Toast notification on success/failure

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

app/modules/prospecting/static/admin/js/prospects.js

@@ -152,6 +152,18 @@ function prospectsList() {
             if (this.pagination.page > 1) { this.pagination.page--; this.loadProspects(); }
         },
 
+        async deleteProspect(prospect) {
+            var name = prospect.business_name || prospect.domain_name || 'this prospect';
+            if (!confirm('Delete "' + name + '"? This cannot be undone.')) return;
+            try {
+                await apiClient.delete('/admin/prospecting/prospects/' + prospect.id);
+                Utils.showToast('Prospect deleted', 'success');
+                await this.loadProspects();
+            } catch (err) {
+                Utils.showToast('Failed: ' + err.message, 'error');
+            }
+        },
+
         statusBadgeClass(status) {
             const classes = {
                 pending: 'text-yellow-700 bg-yellow-100 dark:text-yellow-100 dark:bg-yellow-700',