Add payments with TDS, invoice detail view and filterable History (Phase E2)

- Migration M8 adds payments (cash, TDS, mode, reference). Payment status is derived, never stored: unpaid, partially paid, paid, or overdue. Overpayment is rejected, TDS counts toward settling, and only issued invoices accept payments. list_invoices and get_invoice carry the paid, TDS and balance summary.
- New invoice detail view: archived-PDF preview, payments list, Record payment modal, Export, Duplicate (as a draft), Re-render and Cancel. An invoice with payments cannot be cancelled until they are deleted.
- History gets search, status, financial-year, month and client filters, sortable columns, pagination, footer totals and an FY summary. Cancelled invoices are excluded from totals. The per-row archive-status calls are gone; archiving is on the detail page.
- Rust tests for payments and the list summary; vitest for fiscal-year, money, filter and duplicate helpers.

PDF output and fingerprint goldens are unchanged. The new UI has not been run in a webview yet.

src/lib/api.ts

@@ -11,6 +11,7 @@ import type {
   Settings,
 } from "./types";
 import type { LogoAsset } from "./logo";
+import type { Payment, PaymentInput } from "./payments";
 import type { FontInspection, ImportMeta, RemoveOutcome, UserFontRow } from "./fontImport";
 
 export interface ArchiveStatus {
@@ -49,6 +50,10 @@ export const api = {
   listInvoices: () => invoke<InvoiceSummary[]>("list_invoices"),
   getInvoice: (id: number) => invoke<Invoice>("get_invoice", { id }),
 
+  recordPayment: (input: PaymentInput) => invoke<Payment>("record_payment", { input }),
+  listPayments: (invoiceId: number) => invoke<Payment[]>("list_payments", { invoiceId }),
+  deletePayment: (id: number) => invoke<void>("delete_payment", { id }),
+
   saveDraft: (id: number | null, payload: unknown) =>
     invoke<number>("save_draft", { id, payload }),
   listDrafts: () => invoke<DraftSummary[]>("list_drafts"),