feat(get_paid): one card showing everything the server knows

[BullishNode]

There is no separate 'payment' — only the invoice — so the transaction
card stops linking out to a second screen and becomes the single place a
merchant reads everything about an entry, for every product (Lightning
address, invoices, Payment Page, POS).

• View-invoice button removed; the card renders every field of the
  history contract: receipt id (copyable, never presented as a chain
  txid), settlement kind stated explicitly ('Settled as: Bitcoin' instead
  of an absent section), per-leg network, and the fiat-conversion
  override with all five 0.3 reasons — ambiguous_create now mapped and
  worded instead of funneling to unknown
• invoice facts merged in via the invoices facade (locator-guarded,
  fail-silent): status with supporting lines only when they add
  information, face amount, pricing, paid/remaining/overpaid, tolerance,
  rate locked until, absolute expiry, paid via/at, accepted rails, and a
  compact per-event payment history
• payer instructions render last, collapsed: lightning invoice,
  addresses, BIP21, per-rail payer amounts, quote rails, and the live
  payer quote rate — labelled distinctly from the R1 reference and R2
  executed rates so the three can never be misread
• organized into titled sections in merchant-priority order; every fact
  appears exactly once; long values truncate in place and copy in full;
  empty sections render nothing
• shared invoice copy moved to the invoices public boundary
  (invoice_copy.dart) so Get Paid reuses it without cross-feature reach

Gates: analyze --fatal-infos clean; 516 tests green (21 new card tests).

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