Audit short-term: currency preview, date bounds, success destination, safe-area

- H3: Live currency preview below currency inputs shows the value formatted
  with thousands separators (en-US, USD) using Intl.NumberFormat. Skipped
  inside matrix cells to keep the Y1 monthly table compact.
- M1: Date inputs now apply min/max bounds. Default window is 1900-01-01 to
  2100-12-31; per-field override via FieldConfig.min/max as ISO strings.
- H6: On successful submit, replace the form with a SuccessDestination card
  (large checkmark, org name, "Submit another" + "safe to close" affordance).
  Prevents accidental duplicate submits from back-button / autofill replay.
- M6: Sticky submit bar respects iOS safe-area-inset-bottom.

FieldRenderer now takes a control prop so the currency preview can subscribe
to its single field via useWatch without re-rendering the whole form.

components/fields/FieldRenderer.tsx

@@ -1,12 +1,20 @@
 "use client";
 
+import { useWatch } from "react-hook-form";
 import type { FieldConfig, SelectOption } from "@/types/form";
-import type { UseFormRegister, FieldValues, FieldErrors } from "react-hook-form";
+import type {
+  UseFormRegister,
+  FieldValues,
+  FieldErrors,
+  Control,
+} from "react-hook-form";
 
 interface FieldRendererProps {
   field: FieldConfig;
   register: UseFormRegister<FieldValues>;
   errors: FieldErrors;
+  /** Form control — required for currency live-preview formatting. */
+  control: Control<FieldValues>;
   /** For readonly display fields, the value to render. */
   readonlyValue?: unknown;
   /**
@@ -17,6 +25,9 @@ interface FieldRendererProps {
   resolvedOptions?: SelectOption[];
 }
 
+const DATE_MIN_DEFAULT = "1900-01-01";
+const DATE_MAX_DEFAULT = "2100-12-31";
+
 /**
  * Renders a single field appropriate to its `type`. All inputs share a common
  * accessibility scaffold: a real <label htmlFor>, aria-describedby pointing
@@ -34,6 +45,7 @@ export function FieldRenderer({
   field,
   register,
   errors,
+  control,
   readonlyValue,
   resolvedOptions,
 }: FieldRendererProps) {
@@ -263,17 +275,43 @@ export function FieldRenderer({
             </span>
           )}
         </div>
+        {field.type === "currency" && (
+          <CurrencyPreview control={control} name={field.name} />
+        )}
         {field.help && <Help id={helpId!}>{field.help}</Help>}
         {errorMsg && <ErrorText id={errorId!}>{errorMsg}</ErrorText>}
       </div>
     );
   }
 
-  // ── Default: text-like (text / email / phone / date) ────────────────────
+  // ── Date ────────────────────────────────────────────────────────────────
+  if (field.type === "date") {
+    const dateMin = typeof field.min === "string" ? field.min : DATE_MIN_DEFAULT;
+    const dateMax = typeof field.max === "string" ? field.max : DATE_MAX_DEFAULT;
+    return (
+      <div className="space-y-1">
+        <Label id={id} field={field} />
+        <input
+          id={id}
+          type="date"
+          aria-describedby={describedBy}
+          aria-invalid={errorMsg ? true : undefined}
+          aria-required={field.required || undefined}
+          min={dateMin}
+          max={dateMax}
+          {...register(field.name, { required: requiredOpt })}
+          className={baseInputClass}
+        />
+        {field.help && <Help id={helpId!}>{field.help}</Help>}
+        {errorMsg && <ErrorText id={errorId!}>{errorMsg}</ErrorText>}
+      </div>
+    );
+  }
+
+  // ── Default: text-like (text / email / phone) ───────────────────────────
   const inputType =
     field.type === "email" ? "email" :
     field.type === "phone" ? "tel" :
-    field.type === "date" ? "date" :
     "text";
 
   return (
@@ -301,6 +339,30 @@ export function FieldRenderer({
   );
 }
 
+const currencyFmt = new Intl.NumberFormat("en-US", {
+  style: "currency",
+  currency: "USD",
+  maximumFractionDigits: 2,
+});
+
+function CurrencyPreview({
+  control,
+  name,
+}: {
+  control: Control<FieldValues>;
+  name: string;
+}) {
+  const raw = useWatch({ control, name });
+  if (raw === undefined || raw === null || raw === "") return null;
+  const n = typeof raw === "number" ? raw : Number(raw);
+  if (!Number.isFinite(n)) return null;
+  return (
+    <p className="text-xs tabular-nums text-ink-mute" aria-live="polite">
+      {currencyFmt.format(n)}
+    </p>
+  );
+}
+
 function Label({ id, field }: { id: string; field: FieldConfig }) {
   return (
     <label htmlFor={id} className="block text-sm font-medium text-ink">