fix(ui): prevent duplicate key error in issues table

Svelte each block key used , but when
two issues share the same message text (e.g. 'Main content area
is completely blank') and have no id, the key collides.

Fix: use composite key
as fallback when issue.id is missing.

frontend/src/routes/validation-tasks/[policyId]/runs/[runId]/+page.svelte

@@ -386,7 +386,7 @@
 											</tr>
 										</thead>
 										<tbody class="divide-y divide-gray-200">
-											{#each dbIssues as issue (issue.id || issue.message)}
+											{#each dbIssues as issue (issue.id || `${issue.message}-${issue.location || ''}-${issue.severity || ''}`)}
 												<tr class="hover:bg-gray-50">
 													<td class="px-3 py-2 whitespace-nowrap">
 														<span class="inline-flex items-center px-2 py-0.5 rounded text-xs font-medium {getSeverityClass(issue.severity || issue.level)}">