feat(05-01): create FinanceRow component

- 2-line stacked row for invoice and payment lists (D-06)
- Exports FinanceRow + FinanceRowProps per UI-SPEC contract
- Supports amountTone destructive/positive/default variants
- No priority stripe, no interactive handlers (read-only per D-22)
- Phase comment block per Phase 3/4 convention

components/mobile/FinanceRow.tsx

@@ -0,0 +1,43 @@
+'use client';
+
+/* FinanceRow — phase 05 (FIN-02).
+ * Purpose: 2-line stacked row used by Open Invoices and Recent Payments lists.
+ *   Line 1: primary label (left, text-sm font-semibold truncate) + amount (right, text-sm font-semibold).
+ *   Line 2: secondary metadata (left, text-xs text-muted-foreground) + optional date (right, text-xs text-muted-foreground).
+ * Pure presentational — parent owns the data.
+ * Props: see FinanceRowProps. */
+
+import { cn } from '@/lib/utils';
+
+export interface FinanceRowProps {
+  /** Primary label on line 1 (e.g., customer name) */
+  primary: string;
+  /** Amount string already formatted (e.g., "$1,234") — caller passes fmt$(value) */
+  amount: string;
+  /** Secondary metadata on line 2 (e.g., "#1234 · Due May 1" or just a date) */
+  secondary?: React.ReactNode;
+  /** Optional right-side date on line 2 (used by payment rows; invoice rows put date in `secondary`) */
+  rightSecondary?: React.ReactNode;
+  /** When true, amount renders in destructive color (overdue invoices). */
+  amountTone?: 'default' | 'destructive' | 'positive';
+}
+
+export function FinanceRow({ primary, amount, secondary, rightSecondary, amountTone = 'default' }: FinanceRowProps) {
+  const amountClass = cn(
+    'text-sm font-semibold shrink-0',
+    amountTone === 'destructive' && 'text-destructive',
+    amountTone === 'positive' && 'text-emerald-600'
+  );
+  return (
+    <div className="px-4 py-3 flex items-start justify-between gap-2 hover:bg-muted/50 transition-colors">
+      <div className="flex-1 min-w-0">
+        <p className="text-sm font-semibold truncate">{primary}</p>
+        {secondary && <p className="text-xs text-muted-foreground mt-0.5">{secondary}</p>}
+      </div>
+      <div className="shrink-0 text-right">
+        <p className={amountClass}>{amount}</p>
+        {rightSecondary && <p className="text-xs text-muted-foreground mt-0.5">{rightSecondary}</p>}
+      </div>
+    </div>
+  );
+}