fix(orders): three defects found reviewing my own branch

None of these were caught by 105 green tests, because the code they live in was
barely tested and the HTTP path was not tested at all.

1. reconcilePendingOrders hardcoded category 'dining', so any order resolved
   through the deferred path booked as dining regardless of merchant — a
   Woolworths grocery order that parks and later reconciles was misfiled.
   That reintroduced, through the back door, exactly the misfiling
   resolveCategory() exists to prevent. Now calls it.

2. reconcileCardLeg never marked a statement line as consumed, so two orders on
   the same card inside the +/-4 day window both bound to the same charge and
   each booked its own credits remainder — double-counting spend. At 10-15
   orders a month on one card that is not a corner case. Migration 0020 adds
   matched_transaction_id with a unique index; the matcher now excludes lines
   already claimed.

3. The ingest API returned HTTP 200 for every parse failure, and the Slack
   alert fires only on non-200. So the single most likely production failure —
   a provider template change breaking every order at once — was completely
   silent. Split into NotAReceiptError (promotions, delivery updates, refund
   and adjustment notices: 200, silent, expected traffic) and OrderParseError
   (it IS a receipt and would not parse: 422, alerts).

Also: order_reference now anchors on Uber's own tripReference cell rather than
'first UUID in the document'. I had claimed to verify that the first UUID was
always the order UUID; that check compared against zero samples and was
vacuous. tripReference is present in all 29 captured receipts and, for ue-00,
equals the UUID the PDF redirect resolves to. The positional fallback remains
but only flags when there is genuine ambiguity.

Adds the API route's first tests — auth gate and error taxonomy — plus
anchoring regressions. 63 unit + 53 integration green on five consecutive runs;
corpus holds at 63/65.

src/__tests__/integration/order-ingest-api.test.ts

@@ -0,0 +1,106 @@
+import { describe, it, expect, beforeAll } from "vitest";
+import { readFileSync } from "fs";
+import { resolve } from "path";
+import { queryRaw } from "../../lib/db";
+
+/**
+ * The HTTP path had no tests at all — which is how three defects reached the
+ * branch through a suite of 105 green ones. These exercise the route handler
+ * directly (no server needed) so the auth gate and the error taxonomy are
+ * actually covered.
+ */
+const dir = resolve(__dirname, "../fixtures/orders/real");
+const html = (f: string) => readFileSync(resolve(dir, `${f}.html`), "utf-8");
+
+const TOKEN = "test-ingest-token";
+let POST: any;
+
+const req = (body: unknown, token: string | null = TOKEN) =>
+  ({
+    headers: { get: (h: string) => (h === "x-ingest-token" ? token : null) },
+    json: async () => body,
+  }) as any;
+
+beforeAll(async () => {
+  process.env.ORDER_INGEST_TOKEN = TOKEN;
+  ({ POST } = await import("../../app/api/orders/ingest/route"));
+});
+
+describe("ingest API — auth", () => {
+  it("rejects a missing token", async () => {
+    const res = await POST(req({ html: "x", meta: {} }, null));
+    expect(res.status).toBe(401);
+  });
+
+  it("rejects a wrong token", async () => {
+    const res = await POST(req({ html: "x", meta: {} }, "nope"));
+    expect(res.status).toBe(401);
+  });
+
+  it("rejects a malformed body", async () => {
+    const res = await POST(req({ html: "only html" }));
+    expect(res.status).toBe(400);
+  });
+});
+
+describe("ingest API — error taxonomy", () => {
+  const meta = (over = {}) => ({
+    messageId: `api-${Math.random().toString(36).slice(2)}`,
+    subject: "Order Confirmation for Siddharth from Mad Mex",
+    receivedAt: "2026-07-16T03:34:00Z",
+    sender: "DoorDash Order <no-reply@doordash.com>",
+    ...over,
+  });
+
+  it("a non-receipt is 200 and silent — it must not alert", async () => {
+    // A newsletter: real traffic, correctly ignored.
+    const res = await POST(req({ html: html("dd-01"), meta: meta({ subject: "Newsletter", sender: "promo@example.com" }) }));
+    expect(res.status).toBe(200);
+    expect((await res.json()).kind).toBe("skipped");
+  });
+
+  it("an adjustment notice is 200 and silent", async () => {
+    const res = await POST(req({
+      html: html("dd-08"),
+      meta: meta({ subject: "Order Confirmation for Siddharth from ALDI" }),
+    }));
+    expect(res.status).toBe(200);
+    expect((await res.json()).kind).toBe("skipped");
+  });
+
+  it("a receipt that cannot be parsed is 422 so it ALERTS", async () => {
+    // A DoorDash receipt with its totals stripped out — i.e. what a provider
+    // template change looks like. Previously this returned 200 and vanished.
+    const broken = html("dd-01")
+      .replace(/Total Charged/g, "Gesamtbetrag")
+      .replace(/Total:/g, "Summe:");
+    const res = await POST(req({ html: broken, meta: meta() }));
+    expect(res.status).toBe(422);
+    const body = await res.json();
+    expect(body.kind).toBe("parse_failed");
+    expect(body.reason).toMatch(/total/i);
+  });
+
+  it("a refund is routed to the amendment path, not ingestion", async () => {
+    const res = await POST(req({
+      html: html("ue-05"),
+      meta: meta({ subject: "Your Tuesday evening order with Uber Eats", sender: "uber.com" }),
+      dryRun: true,
+    }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.kind).toBe("amendment");
+    expect(body.amendment.new_total).toBeCloseTo(45.73, 2);
+  });
+
+  it("a good receipt ingests", async () => {
+    await queryRaw(`DELETE FROM expense_metadata WHERE source = 'email'`);
+    await queryRaw(`DELETE FROM transactions WHERE description LIKE 'Order - %'`);
+    const res = await POST(req({ html: html("dd-01"), meta: meta({ messageId: "api-ok-1" }) }));
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body.kind).toBe("order");
+    expect(body.total).toBe(14.64);
+    expect(body.transactionId).not.toBeNull();
+  });
+});

src/__tests__/integration/order-ingestion.test.ts

@@ -10,6 +10,7 @@ import {
   parseOrderAmendment,
   applyOrderAmendment,
   OrderParseError,
+  NotAReceiptError,
   type MessageMeta,
 } from "../../lib/order-ingestion";
 import { EXCLUDE_NON_SPEND } from "../../lib/analytics-sql";
@@ -113,9 +114,12 @@ describe("Order parsing — real receipts", () => {
   });
 
   it("rejects an order-adjustment notice rather than booking $0.00", () => {
+    // NotAReceiptError, not OrderParseError: this is expected traffic, so it
+    // must be skipped silently. Only a receipt that fails to parse should
+    // alert — see the ingest API's error taxonomy.
     expect(() =>
       parseOrderHTML(html("dd-08"), meta({ subject: "Order Confirmation for Siddharth from ALDI" }))
-    ).toThrow(OrderParseError);
+    ).toThrow(NotAReceiptError);
   });
 
   it("rejects a refund notice rather than inserting a duplicate order", () => {