simple-mode-fields* rendered its single account row by rebinding the form cursor to a
synthetic MapCursor rooted at accounts[0] (faking a deep starting position). Replace that
with explicit-data rendering: account-field-name builds the exact field names the cursor
would produce at [:step-params :transaction/accounts 0 field] (via path->name2), and
account-field-errors reads errors from the same path -- no re-rooted cursor.
This is the render-fn rewrite the earlier with-field-default shortcut couldn't be (that
mutated the cursor and broke the simple-mode swap). Scorecard: faked cursor roots 2 -> 0
(both heuristic-1 items now clear for this modal). Parity held: swap spec 6/6 (its vendor
tests run in simple mode), Shared Location save green, full suite 31 pass / no regression.
Bryce
57f3b63b6a