Best Value: one price age instead of a source breakdown

Dated pricing had crowded More info and the station rows, and most of the
extra copy described a distinction the data cannot make: every station
carries a single station-wide timestamp, so "grade-specific vs
station-wide" never varied in practice.

- More info shows one row, "Price updated 28h ago" (or "Not provided"),
  replacing the separate station-report and fuel-update-time rows and the
  blanket "price freshness is not confirmed" label.
- Rows and the detail sheet stay quiet when a saving is shown; only an
  ineligible comparison explains itself. Provisional savings already read
  as estimates from the capsule, so the fuel-named warning lines are gone.
- Freshness/eligibility logic is unchanged: it still gates the baseline and
  still supports grade-specific timestamps for when the relay emits them.
- Tests updated; localisation keys for the removed copy dropped.

FuelBoard/StationDetailView.swift

@@ -213,20 +213,10 @@ struct StationDetailView: View {
                         LabeledContent("Distance", value: distance.labelWithReturn(unit: distanceUnit))
                             .monospacedDigit()
                     }
-                    if let reportAge = priceFreshness.stationReportAgeLabel {
-                        LabeledContent("Station price report", value: reportAge)
-                            .monospacedDigit()
-                    }
-                    LabeledContent("\(selectedFuel.displayName) update time", value: priceFreshness.selectedFuelUpdateLabel)
+                    LabeledContent("Price updated", value: priceFreshness.updateAgeLabel)
                         .monospacedDigit()
                     LabeledContent("\(selectedFuel.displayName) price", value: selectedFuelPriceText)
                         .monospacedDigit()
-                    if priceFreshness.warning {
-                        Label("Price freshness is not confirmed for \(selectedFuel.displayName)",
-                              systemImage: "exclamationmark.triangle.fill")
-                            .font(.subheadline.weight(.semibold))
-                            .foregroundStyle(.orange)
-                    }
                     ForEach(StationNotice.notices(for: station)) { notice in
                         Label(notice.title, systemImage: notice.symbolName)
                             .font(.subheadline.weight(.semibold))