fix(idle): drop the redundant 'Available: N sats' line from the centre

The machine's balance already sits in App.vue's top-right status chip.
Repeated in the centre — right above the holder's card chip on a
tap-to-enter session — it reads as *their* balance ('Available: 0 sats'
next to a card showing 959,242 sats). Keep only the buy/sell rates there.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

apps/machine/src/views/IdleView.vue

@@ -74,16 +74,12 @@ function handleCashOut() {
           >Just Bitcoin</Badge
         >
       </div>
-      <!-- Balance + Commission rates -->
+      <!-- Commission rates. The machine's own balance is NOT repeated here: App.vue
+           already shows it in the top-right status chip, and next to the holder's
+           card chip an "Available: N sats" line reads as *their* balance. -->
       <div
         class="mt-1 flex flex-wrap items-center justify-center gap-2 lg:gap-4 text-[11px] lg:text-[2vh] text-muted-foreground"
       >
-        <span v-if="atmStore.balanceSats !== null">
-          Available:
-          <span class="font-bold text-primary"
-            >{{ atmStore.balanceSats.toLocaleString() }} sats</span
-          >
-        </span>
         <span>
           Buy:
           <span class="font-bold text-bitcoin"