Add QA evidence drilldown

frontend/src/styles/app.css

@@ -1483,6 +1483,7 @@ button.entity-card {
 
 .quality-summary-surface,
 .quality-evidence-surface,
+.quality-drilldown-surface,
 .quality-control-surface,
 .quality-history-surface {
   min-width: 0;
@@ -1500,6 +1501,21 @@ button.entity-card {
   background: #f8fbf9;
 }
 
+.quality-drilldown-surface {
+  display: grid;
+  gap: 0.72rem;
+  background: linear-gradient(180deg, #ffffff, #f7fbf8);
+}
+
+.quality-drilldown-surface .panel-title-row {
+  align-items: start;
+}
+
+.quality-drilldown-surface .panel-title-row button {
+  width: auto;
+  min-height: 2.35rem;
+}
+
 .quality-control-surface,
 .quality-history-surface {
   display: grid;
@@ -1600,6 +1616,14 @@ button.entity-card {
   margin: 0;
 }
 
+.quality-drilldown-grid,
+.quality-evidence-token-grid,
+.quality-provenance-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
+  gap: 0.58rem;
+}
+
 .quality-summary-grid > div {
   border: 1px solid var(--line);
   border-radius: 8px;
@@ -1615,8 +1639,31 @@ button.entity-card {
   background: #ffffff;
 }
 
+.quality-drilldown-grid > div,
+.quality-evidence-token-grid > div,
+.quality-provenance-grid > div {
+  min-width: 0;
+  border: 1px solid var(--line);
+  border-radius: 8px;
+  padding: 0.68rem;
+  background: #ffffff;
+}
+
+.quality-evidence-token-grid > div {
+  border-color: rgba(15, 118, 110, 0.22);
+  background: linear-gradient(180deg, #f8fcfa, #ffffff);
+}
+
+.quality-evidence-map-handoff,
+.quality-evidence-token-grid > div:nth-child(3) {
+  background: var(--accent-soft);
+}
+
 .quality-summary-grid span,
 .quality-handoff-grid span,
+.quality-drilldown-grid span,
+.quality-evidence-token-grid span,
+.quality-provenance-grid span,
 .quality-score-row span,
 .latest-export-card span,
 .metric-list span {
@@ -1643,6 +1690,52 @@ button.entity-card {
   line-height: 1.2;
 }
 
+.quality-drilldown-grid strong,
+.quality-evidence-token-grid strong {
+  display: block;
+  margin-top: 0.22rem;
+  overflow: hidden;
+  color: var(--ink);
+  font-size: 0.9rem;
+  line-height: 1.25;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.quality-drilldown-grid p,
+.quality-evidence-token-grid p {
+  margin: 0.24rem 0 0;
+  color: var(--muted);
+  font-size: 0.8rem;
+  line-height: 1.35;
+  overflow-wrap: anywhere;
+}
+
+.quality-provenance-pre {
+  max-height: 11rem;
+  margin: 0.38rem 0 0;
+  overflow: auto;
+  border: 1px solid var(--line);
+  border-radius: 7px;
+  padding: 0.58rem;
+  background: #0f172a;
+  color: #e2e8f0;
+  font-size: 0.75rem;
+  line-height: 1.35;
+  white-space: pre-wrap;
+  overflow-wrap: anywhere;
+}
+
+.quality-check-actions {
+  display: flex;
+  justify-content: flex-end;
+}
+
+.quality-check-actions button {
+  width: auto;
+  min-height: 2.15rem;
+}
+
 .quality-dataset-name,
 .quality-check-dataset-link {
   overflow-wrap: anywhere;