fix(cash-in): restore cancel button and add displayingQR timeout

Cancel button is now always visible during the cash-in flow. The state
machine routes CANCEL to confirmAbandon when bills are present, so the
user always has an exit path with appropriate warnings. Also adds a
5-minute auto-timeout on displayingQR and allows cancel during
generatingNdebit.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/machine/src/views/CashInView.vue

@@ -16,15 +16,19 @@ const atmStore = useAtmStore()
 const isElectron = typeof window !== 'undefined' && window.electronAPI !== undefined
 
 // Whether the header cancel button should be visible
-// Hide after bills are inserted — state machine routes to confirmAbandon instead
+// State machine routes CANCEL to confirmAbandon when bills are present
 const showCancelButton = computed(() => {
   const state = atmStore.nestedState
-  const hasBills = (atmStore.context?.billsInserted.length ?? 0) > 0
-  // Show in fetchingRate (no bills yet) and insertingBills only before bills are in
-  if (state === 'fetchingRate') return true
-  if (state === 'insertingBills' && !hasBills) return true
-  if (state === 'error' && !hasBills) return true
-  // Hide when bills are in the cash box
+  // Show cancel in states where user might want to exit
+  // State machine handles routing: no bills → idle, bills → confirmAbandon
+  if (
+    state === 'fetchingRate' ||
+    state === 'insertingBills' ||
+    state === 'generatingNdebit' ||
+    state === 'displayingQR' ||
+    state === 'error'
+  )
+    return true
   return false
 })
 

packages/state-machine/src/machine.ts

@@ -449,7 +449,6 @@ export function createATMMachine(
             },
           },
           generatingNdebit: {
-            // No CANCEL here — bills are already in the cash box
             invoke: {
               src: 'generateNdebit',
               input: ({ context }) => context,
@@ -465,8 +464,14 @@ export function createATMMachine(
                 actions: 'setError',
               },
             },
+            on: {
+              CANCEL: 'confirmAbandon',
+            },
           },
           displayingQR: {
+            after: {
+              TIMEOUT_MS: 'confirmAbandon',
+            },
             on: {
               PAYMENT_RECEIVED: {
                 target: 'askForReceipt',