Improve map overlay ergonomics

frontend/src/styles/app.css

@@ -797,6 +797,14 @@ section > div:not(.map-controls):not(.feature-inspector):not(.quick-action-grid)
   gap: 0.55rem;
 }
 
+.panel-title-row {
+  display: flex;
+}
+
+section > .panel-title-row {
+  display: flex !important;
+}
+
 section button + button {
   margin-top: 0.45rem;
 }
@@ -1178,6 +1186,10 @@ button.entity-card {
   line-height: 1.4;
 }
 
+.map-empty-state {
+  margin-bottom: 0.85rem;
+}
+
 .export-action-grid {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
@@ -1287,6 +1299,58 @@ button.entity-card {
   font-size: 0.84rem;
 }
 
+.layer-provenance-rail {
+  display: grid;
+  grid-template-columns: 0.85fr minmax(0, 1.5fr) 0.85fr;
+  gap: 0.65rem;
+  margin-bottom: 0.85rem;
+}
+
+.layer-provenance-rail > div,
+.feature-property-chip {
+  min-width: 0;
+  border: 1px solid var(--line);
+  border-radius: 7px;
+  padding: 0.58rem 0.68rem;
+  background: #ffffff;
+}
+
+.layer-provenance-rail span,
+.feature-property-chip span {
+  display: block;
+  color: var(--muted);
+  font-size: 0.68rem;
+  font-weight: 800;
+  letter-spacing: 0.05em;
+  text-transform: uppercase;
+}
+
+.layer-provenance-rail strong,
+.feature-property-chip strong {
+  display: block;
+  margin-top: 0.2rem;
+  overflow: hidden;
+  font-size: 0.84rem;
+  line-height: 1.25;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.layer-provenance-rail strong {
+  display: -webkit-box;
+  min-height: 2.1rem;
+  -webkit-box-orient: vertical;
+  -webkit-line-clamp: 2;
+  white-space: normal;
+}
+
+.feature-summary-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
+  gap: 0.55rem;
+  margin-bottom: 0.75rem;
+}
+
 .lab-block + .lab-block {
   margin-top: 0.85rem;
 }
@@ -1508,6 +1572,7 @@ button.entity-card {
 
   .dataset-upload-form,
   .map-toolbar,
+  .layer-provenance-rail,
   .lab-form-grid,
   .quality-summary-grid,
   .quality-score-row,