Fix two stale failing tests

- TestHandleAPIBenchmarkPowerFitRampQueuesBenchmarkPowerFitTasks: ramp-up
  mode intentionally creates a single task (the runner handles 1→N internally
  to avoid redundant repetition of earlier ramp steps). Updated the test to
  expect 1 task and verify RampTotal=3 instead of asserting 3 separate tasks.

- TestBenchmarkPageRendersSavedResultsTable: benchmark page used "Performance
  Results" as heading while the test looked for "Perf Results". Aligned the
  page heading with the shorter label used everywhere else (task reports, etc.).

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

audit/internal/webui/pages.go

@@ -2385,7 +2385,7 @@ function benchmarkRefreshResults() {
 func renderBenchmarkResultsCard(exportDir string) string {
 	maxIdx, runs := loadBenchmarkHistory(exportDir)
 	perf := renderBenchmarkResultsCardFromRuns(
-		"Performance Results",
+		"Perf Results",
 		"Composite score by saved benchmark run and GPU.",
 		"No saved performance benchmark runs yet.",
 		maxIdx,