profiler: add 'Only mismatches' filter to check results

The results view header (live card and snapshot checks) gets an Only
mismatches checkbox that hides all passing files and keeps only failures
and errors; when everything passes under the filter, a 'No mismatches'
note is shown instead. The pass/fail/error summary always reflects all
results. Helps with large profiles on cards where most files match.
SW cache v86 -> v87.

frontend/index.html

@@ -848,6 +848,10 @@
 				<div class="flex flex-wrap gap-2 items-center mb-3">
 					<button onclick="profilerBackToList()" class="px-2.5 py-1 text-sm rounded border border-gray-300 dark:border-slate-600 hover:bg-gray-200 dark:hover:bg-slate-700 text-gray-700 dark:text-slate-300" data-l10n="Back to list">Back to list</button>
 					<span id="profiler-results-title" class="text-sm font-semibold"></span>
+					<label class="ml-auto flex items-center gap-1 text-xs text-gray-600 dark:text-slate-400 cursor-pointer">
+						<input id="profiler-mismatch-only" type="checkbox" onchange="profilerToggleMismatchOnly(this.checked)">
+						<span data-l10n="Only mismatches">Only mismatches</span>
+					</label>
 				</div>
 				<div id="profiler-progress" class="mb-2 text-base font-mono text-gray-600 dark:text-slate-400"></div>
 				<div id="profiler-summary" class="mb-2 text-sm"></div>
@@ -6988,6 +6992,7 @@ let profilerView = 'list';
 let profilerEditId = null;
 let profilerDraft = null;
 let profilerResults = null;
+let profilerMismatchOnly = false;
 let snapshots = [];
 let snapshotViewId = null;
 let _scanTarget = 'profile';
@@ -7932,6 +7937,15 @@ async function profilerCheckSnapshot(i, si) {
 	await profilerRunProfile(p, profilerSnapshotSource(s), p.name + ' — ' + s.name);
 }
 
+function profilerToggleMismatchOnly(checked) {
+	profilerMismatchOnly = checked;
+	profilerRenderResultsView();
+}
+
+function profilerVisibleResults(results, mismatchOnly) {
+	return mismatchOnly ? results.filter(r => r.status !== 'pass') : results;
+}
+
 function profilerRenderResultsView() {
 	if (!profilerResults) return;
 	let passed = 0, failed = 0, errors = 0;
@@ -7943,7 +7957,10 @@ function profilerRenderResultsView() {
 	document.getElementById('profiler-summary').innerHTML = '<span class="text-emerald-600 font-semibold">' + passed + ' ' + t('passed') + '</span>' +
 		' · <span class="text-red-600 font-semibold">' + failed + ' ' + t('failed') + '</span>' +
 		' · <span class="text-yellow-600 font-semibold">' + errors + ' ' + t('errors') + '</span>';
-	document.getElementById('profiler-report').innerHTML = profilerRenderReport(profilerResults);
+	const shown = profilerVisibleResults(profilerResults, profilerMismatchOnly);
+	document.getElementById('profiler-report').innerHTML = shown.length
+		? profilerRenderReport(shown)
+		: '<div class="text-sm text-emerald-600">' + esc(t('No mismatches')) + '</div>';
 }
 
 function profilerLiveSource() {
@@ -8730,6 +8747,8 @@ const LANG_RU = {
 	'passed': 'пройдено',
 	'failed': 'не пройдено',
 	'errors': 'ошибок',
+	'Only mismatches': 'Только расхождения',
+	'No mismatches': 'Расхождений нет',
 	'expected': 'ожидалось',
 	'actual': 'фактически',
 	'HTTP OTA': 'HTTP OTA',