banner: key by value so tip fades out on dismiss

The banner sits in a single if-let slot; without an identity key, clearing a
tip that was covering a network/offline banner swapped content in place with
no transition (instantly vanishing). Keying the banner by its value (.id)
makes every change — tip→network or tip→nil — run the shared removal
transition, so the tip slides up and fades out when it auto-dismisses or is
tapped.

FuelBoard/ContentView.swift

@@ -5,7 +5,7 @@ import WidgetKit
 /// The single floating notification banner. Network/offline state and tip
 /// outcomes all funnel through ONE style and render via the same chrome in
 /// ContentView — never pushing layout, always overlaid.
-enum AppBanner: Equatable {
+enum AppBanner: Hashable {
     case offlineDump(date: String)
     case connectionProblem
     case tip(TipStore.TipOutcome)
@@ -491,6 +491,10 @@ struct ContentView: View {
                     // main content so it doesn't cover or block the list/pill
                     // beneath it.
                     floatingBanner(banner)
+                        // Key by value so ANY change (tip→network, tip→nil)
+                        // runs the removal transition (fade/slide-out) instead
+                        // of silently swapping content in place.
+                        .id(banner)
                         .padding(.top, geo.safeAreaInsets.top + 10)
                         .transition(.asymmetric(
                             insertion: .move(edge: .top).combined(with: .opacity),

FuelBoard/SettingsView.swift

@@ -604,7 +604,7 @@ final class TipStore: ObservableObject {
     ]
 
     /// A banner outcome: the exact copy to show plus its icon + tint.
-    struct TipOutcome: Equatable {
+    struct TipOutcome: Hashable {
         let message: String
         let icon: String
         let tint: Color