Stations tab: explainer styled like the Favourites cheapest callout

The N/TOTAL stations-updated explainer now sits in a plain caption Section
cell at the bottom of the tab (font .caption, secondary) — matching the
Favourites tab's bottom callout instead of rendering as a section footer.

FuelBoard/StationsView.swift

@@ -137,14 +137,12 @@ struct StationsView: View {
                     }
                 }
 
-                // Bottom-of-tab explainer (moved from the top 2026-08-16):
-                // own section so the type-checker isn't asked to type the
-                // full stations section AND its footer in one expression.
+                // Bottom-of-tab explainer (moved from the top 2026-08-16),
+                // styled like the Favourites tab's cheapest callout: a caption
+                // paragraph in its own section cell.
                 Section {
-                    EmptyView()
-                } footer: {
                     Text(footerCaption)
-                        .font(.footnote)
+                        .font(.caption)
                         .foregroundStyle(.secondary)
                 }