fix(tokens): recompute the net transfer on re-entry

The private `netTransferAmount` producer deferred to
`State.confirmedNetTransferAmount` — its own output from a previous trip
through the entry screen — while `enteredAmount` and `feeAmount` beside it
recomputed from the live amount delegate. All three feed the same
`OnAmountAccepted` event, so a second pass produced a receipt that mixed
the new entry with the old total: enter $1, go back, enter $0.50, and the
receipt paired a $0.50 debit and a $0.005 fee with a $0.99 "You Receive".

The cache-first read is a leftover from before #829, when a single getter
on `State` served both roles and the keypad lived on `State` too; there it
was what pinned the number once accepted. The delegate split gave that
freeze its own home in `State.netTransferAmount`, but the producer copy
kept the prefix. `enteredAmount` and `feeAmount` were rewritten during that
split and came out cache-free, which is the asymmetry behind the bug.

Affects v1's Sell path the same way, so it is left ungated — a wrong number
is not a v1 pixel worth preserving.

Author: bmc08gt

apps/flipcash/shared/tokens/src/main/kotlin/com/flipcash/app/tokens/ui/SwapViewModel.kt

@@ -493,9 +493,19 @@ class SwapViewModel @Inject constructor(
             return enteredAmount.launchpadSellFee(bps)
         }
 
-    /** What the user actually receives: entered minus the fee, unless the fee rides on top. */
+    /**
+     * What the user actually receives: entered minus the fee, unless the fee rides on top.
+     *
+     * Always recomputed from the live entry rather than read back from
+     * [State.confirmedNetTransferAmount], because this getter is what *produces* that snapshot --
+     * [enteredAmount] and [feeAmount] feed the same event and recompute the same way. Deferring to
+     * the previous confirmation made a second trip through the entry screen re-confirm the first
+     * trip's total: enter $1, go back, enter $0.50, and the receipt paired a $0.50 debit and a
+     * $0.005 fee with a $0.99 "You Receive". Readers that need the snapshot after the entry screen
+     * is gone use [State.netTransferAmount], which is where the caching belongs.
+     */
     private val netTransferAmount: Fiat
-        get() = stateFlow.value.confirmedNetTransferAmount ?: when {
+        get() = when {
             stateFlow.value.purpose is SwapPurpose.BalanceIncrease -> enteredAmount
             stateFlow.value.isConvertingFromDollars -> enteredAmount
             else -> Fiat(