Show the saving in the listing capsule on its own line

Station and Favourite rows share one capsule, so both now read
"Save / £3.10" and "Costs / £1.20 more" instead of the amount-free
"Saves" / "Costs more". "(approx.)" is appended on its own line when the
journey behind the figure was estimated. Break even carries no figure —
±£0.05 is noise — so it stays a single line unless the qualifier adds one.

- Split `listingCapsuleHeadline()` into a structured `ListingVerdict`
  (headline / amount / qualifier) drawn as one Text per line, so where the
  capsule breaks is decided by the data rather than by the width the price
  column happened to hand it: the figure can never straddle two lines.
- The capsule's shape follows its line count: one line stays a Capsule, two
  or more switch to a rounded rect at 8pt, whose corners do not crowd a
  taller block the way a pill's semicircular ends do.
- The Key sheet's legend renders the same component with `showsAmount:
  false`, so it demonstrates the wording without displaying the placeholder
  £1.00 figure it was built from.
- The new words ("Save", "Costs", "(approx.)", "%@ more") go into
  Localizable.strings so the copy editor owns them; amounts run through
  FuelSavingsFormat.money and the amount line is monospaced.
- VoiceOver keeps the single-line form, since a drawn break is a pause
  mid-phrase when spoken.

Tests cover the line structure for all four statuses, the estimated
qualifier and the amount-free legend. Pixel measurement on the simulator
confirms the shape rule: one line measures a radius of h/2 (a pill), two
lines measure 8pt, in both light and dark.

FuelBoardTests/Tests/FuelBoardSharedTests/FuelSavingsEstimateTests.swift

@@ -18,7 +18,7 @@ final class FuelSavingsEstimateTests: XCTestCase {
     )
     private let amount = FuelSavingsFillAmount(value: 40, unit: .pounds)
 
-    func testListingCapsuleUsesSixShortFinancialVerdictsWithoutAmounts() {
+    func testListingCapsulePutsTheFigureOnItsOwnLine() {
         func result(_ status: FuelSavingsStatus, _ confidence: JourneyConfidence) -> FuelSavingsResult {
             FuelSavingsResult(
                 fillLitres: 30,
@@ -31,12 +31,33 @@ final class FuelSavingsEstimateTests: XCTestCase {
             )
         }
 
-        XCTAssertEqual(result(.worthTheDrive, .confirmed).listingCapsuleHeadline(), "Saves")
-        XCTAssertEqual(result(.worthTheDrive, .estimated).listingCapsuleHeadline(), "Saves (approx.)")
-        XCTAssertEqual(result(.notWorthTheDrive, .confirmed).listingCapsuleHeadline(), "Costs more")
-        XCTAssertEqual(result(.notWorthTheDrive, .estimated).listingCapsuleHeadline(), "Costs more (approx.)")
-        XCTAssertEqual(result(.breakEven, .confirmed).listingCapsuleHeadline(), "Break even")
-        XCTAssertEqual(result(.breakEven, .estimated).listingCapsuleHeadline(), "Break even (approx.)")
+        // The figure takes its own line, so the capsule's shape is decided by the
+        // data rather than by how much width the price column hands it.
+        XCTAssertEqual(result(.worthTheDrive, .confirmed).listingVerdict().lines,
+                       ["Save", "£12.50"])
+        XCTAssertEqual(result(.worthTheDrive, .estimated).listingVerdict().lines,
+                       ["Save", "£12.50", "(approx.)"])
+        XCTAssertEqual(result(.notWorthTheDrive, .confirmed).listingVerdict().lines,
+                       ["Costs", "£123.45 more"])
+        XCTAssertEqual(result(.notWorthTheDrive, .estimated).listingVerdict().lines,
+                       ["Costs", "£123.45 more", "(approx.)"])
+
+        // Break even carries no figure — ±£0.05 is noise — so it stays one line
+        // when confirmed and gains a second only for the estimate qualifier.
+        XCTAssertEqual(result(.breakEven, .confirmed).listingVerdict().lines, ["Break even"])
+        XCTAssertEqual(result(.breakEven, .estimated).listingVerdict().lines,
+                       ["Break even", "(approx.)"])
+        XCTAssertEqual(result(.baseline, .confirmed).listingVerdict().lines, ["Closest station"])
+
+        // The Key sheet's legend demonstrates the wording, never a figure.
+        XCTAssertEqual(
+            result(.notWorthTheDrive, .confirmed).listingVerdict(showsAmount: false).lines,
+            ["Costs"]
+        )
+
+        // VoiceOver keeps a single line: a drawn break is a spoken pause.
+        XCTAssertEqual(result(.worthTheDrive, .estimated).listingCapsuleHeadline(),
+                       "Save £12.50 (approx.)")
     }
 
     func testDetailCapsulePlacesApproximationAfterTheFinancialResult() {