Show expected vs actual pace/HR per lap in the Review Queue

Activities recorded from a structured Garmin workout carry a workoutId;
when its steps line up 1:1 with the recorded laps, the per-step target
pace/HR zone is resolved (via a Karvonen lookup for named zones) and stored
on each lap. The Review Queue plots it against the actual per-lap pace/HR
so the user can eyeball whether a run matches its plan while sorting it.

frontend/src/App.css

@@ -210,6 +210,25 @@ button:disabled {
   margin-top: 0.5rem;
 }
 
+.expected-actual-charts {
+  display: flex;
+  gap: 1rem;
+  flex-wrap: wrap;
+  margin: 0.5rem 0;
+}
+
+.mini-chart {
+  flex: 1 1 220px;
+  min-width: 180px;
+}
+
+.mini-chart-label {
+  display: block;
+  font-size: 0.75rem;
+  color: #9aa0ab;
+  margin-bottom: 0.15rem;
+}
+
 .kinds-table {
   width: 100%;
   border-collapse: collapse;