Test that a reconciliation pass logs nothing once cancelled

A reconciliation pass run with an already cancelled context logs no
warning, so a periodic tick the eviction loop takes after a stop adds
no warning to the one from the pass the stop interrupted.

Model: opus-5-5

internal/imgcache/eviction_internal_test.go

@@ -1077,6 +1077,30 @@ func TestReconciliationWalksStopOnceCancelled(t *testing.T) {
 	}
 }
 
+// TestReconciliationPassLogsNoWarningOnceCancelled checks that a
+// reconciliation pass run with an already cancelled context logs no
+// warning, so a periodic tick the loop takes after a stop adds no
+// warning to the one from the pass the stop interrupted.
+func TestReconciliationPassLogsNoWarningOnceCancelled(t *testing.T) {
+	t.Parallel()
+
+	cache, _ := newEvictionTestCache(t, 1<<30)
+
+	var logBuf bytes.Buffer
+
+	cache.log = slog.New(slog.NewJSONHandler(&logBuf, nil))
+
+	ctx, cancel := context.WithCancel(t.Context())
+	cancel()
+
+	cache.runReconciliationPass(ctx)
+	t.Logf("log output: %s", logBuf.String())
+
+	if strings.Contains(logBuf.String(), `"level":"WARN"`) {
+		t.Errorf("runReconciliationPass logged a warning with a cancelled context")
+	}
+}
+
 // TestEvictSourceBlobExcludesConcurrentStoreOfIdenticalContent exercises
 // the exact TOCTOU window between evictSourceBlob's row-deletion
 // transaction commit and its content file unlink: a concurrent