Best Value page: the button says Continue in both states

The declined state had its own "Not now" label, on the theory that declining
should read as a decision rather than a skip. In practice the toggle above it
already shows which answer is being given, so the second label only added a
second thing to read. The label is now an unconditional Continue for both
states, which also let primaryTitle drop the settings value it no longer
consulted.

Nothing else about the page changed: the toggle still hides the sliders when
off, the "can be turned on in Settings" note still appears when declined, and
the settings still save as the controls move.

Verified on the simulator (OCR of the rendered screens): the announcement page,
and the onboarding page with the toggle both off and on, all show Continue as
the bottom button. No "Not now" remains in the app's source. 180 tests,
0 failures.

FuelBoard/OnboardingView.swift

@@ -286,11 +286,9 @@ struct OnboardingView: View {
             // No permission on this page — prices need none. Straight on.
             primaryButton(String(localized: "Continue", comment: "Onboarding continue button")) { page = 4 }
         case 4:
-            // Best Value: the button states the answer the toggle is showing, so
-            // declining reads as a decision rather than a skip. Either way the
-            // settings were saved when the toggle moved, so a swipe past this
-            // page keeps the choice.
-            primaryButton(BestValueIntroContent.primaryTitle(for: fuelSavings)) { page = 5 }
+            // Best Value: the settings were saved when the toggle moved, so a
+            // swipe past this page keeps the choice.
+            primaryButton(BestValueIntroContent.primaryTitle) { page = 5 }
         default:
             primaryButton(String(localized: "Start Using FuelBoard", comment: "Finish onboarding button")) { finish() }
         }