External USD-wallet sends show $0.00 fee while the recipient receives less (fee deducted from amount)

[islandbitcoin]

Device test on TEST (2026-08-15, account rewards_notifier): paid an amountless invoice from an external wallet for $1.10. The app's fee display showed $0.00, the sender was debited $1.10 — and the external wallet received $1.07. IBEX settled with fee-deducted-from-amount semantics (~3¢ routing), while its pre-send estimate for this path returns 0 (the same Estimated Fee: 0.000000 IBEX reports in its error messages on this route).

Two distinct problems:

1. Fee display is wrong: showing $0.00 when the effective fee is nonzero misleads on every external USD-wallet send, MAX or manual.
2. No fee-from-amount disclosure: when the estimate is 0/unavailable on an external send, the recipient can receive less than the entered amount with no warning. The UX should say something like "network fee is deducted from the amount — the recipient may receive slightly less."

Note for #692: this changes its premise for amountless invoices — the feared confirm-time dead-end (amount + fee > balance) doesn't occur on this path because IBEX takes the fee out of the amount; the dead-end analysis applies to fixed-amount invoices. Related: #689 (MAX button), #690 (display floor), flash#480 (fractional balances).

🤖 Generated with Claude Code

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