fix: resolve all 28 findings from the 2026-06-12 full audit (TDD-pinned)

Critical (data integrity):
- warehouse inventory confirm: throw (not return) inside $transaction so a
  failed deficit line rolls back the surplus corrective receipt — retries
  no longer accumulate phantom stock
- warehouse issue confirm: validate batches against the COMBINED quantity
  of all lines (duplicate FIFO-resolved lines drove batches negative)
- attendance delete: restore vacation_used/sick_used for the deleted day
  (in-transaction, clamped at 0)

High:
- auth refresh: terminated sessions (replaced_at only) get a plain 401 —
  the theft branch (family revocation) now fires only on replaced_by_hash
- POST /users strips role_id for non-admin callers (mirrors PUT guard)
- issued-order transition flushes unsaved edits via the full save payload
  when dirty; server contract (items+status in one PUT) pinned
- received-invoices list: usePaginatedQuery + pager (rows 26+ unreachable)
- received-invoice dates: nullableIsoDateString + NaN guard before NAS save
  (Czech-format dates corrupted month/year, orphaned NAS files)
- leave approval skips Czech public holidays and books each calendar year's
  hours against its own balance (mirrors createLeave)

Medium/Low (classes):
- 52 Zod caps aligned to DB column widths across 7 schemas (over-cap input
  500ed at Prisma instead of a Czech 400)
- FK pre-validation: projects update + warehouse receipts/issues return
  Czech 400s instead of P2003 500s
- invoice PDF degrades gracefully when the CNB rate is unavailable
  (recap omitted instead of 500 + lost NAS archival)
- date boundaries: local-day filters (warehouse lists/reports, audit-log),
  @db.Date coercion on invoice dates
- plan updateEntry re-checks the per-cell cap (self-excluding)
- {id} tiebreaks on customers/received-invoices/warehouse-items sorts;
  /items honors the client sort param
- htmlToPdf relaunches once when the shared browser died mid-render
- offer number release parses the year from the document number (cross-year
  finalize+delete left permanent sequence gaps)
- trips/vehicles km fields integer-coerced; AI budget regated to
  settings.company|settings.system; Settings System tab no longer clobbers
  Firma numbering patterns; draft invoices hide the dead PDF button;
  dashboard quick-trip invalidates ["vehicles"]; TOTP secret cap 64;
  audit-log + invoice month buckets day-shift fixes

Docs: corrected the stale "Chromium has no CSS margin-box footers" claim
(html-to-pdf.ts + CLAUDE.md — margin boxes render since Chrome 131); audit
report M3 withdrawn accordingly.

~65 new pinning tests; every finding reproduced RED against the real test
DB before its fix. Suite: 58 files / 634 tests green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/__tests__/html-to-pdf-retry.test.ts

@@ -0,0 +1,73 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+/**
+ * Pinning tests for audit finding M12: a shared Puppeteer browser that
+ * disconnects between getBrowser()'s point-in-time `connected` check and the
+ * actual render must be re-acquired once — instead of failing the request
+ * with a 500 that an immediate retry would have served fine.
+ */
+
+const { launchMock } = vi.hoisted(() => ({ launchMock: vi.fn() }));
+
+vi.mock("puppeteer", () => ({ default: { launch: launchMock } }));
+
+function healthyBrowser(pdfBytes = new Uint8Array([1, 2, 3])) {
+  return {
+    connected: true,
+    newPage: vi.fn(async () => ({
+      setContent: vi.fn(async () => undefined),
+      pdf: vi.fn(async () => pdfBytes),
+      close: vi.fn(async () => undefined),
+    })),
+    close: vi.fn(async () => undefined),
+  };
+}
+
+/** Browser whose connection dies the moment a page is requested — the
+ * post-guard crash window from the finding. */
+function dyingBrowser() {
+  const b = {
+    connected: true,
+    newPage: vi.fn(async () => {
+      b.connected = false;
+      throw new Error("Protocol error (Target.createTarget): Session closed.");
+    }),
+    close: vi.fn(async () => undefined),
+  };
+  return b;
+}
+
+beforeEach(async () => {
+  vi.resetModules();
+  launchMock.mockReset();
+});
+
+describe("htmlToPdf browser re-acquire (audit M12)", () => {
+  it("relaunches once and resolves when the cached browser died mid-acquire", async () => {
+    launchMock
+      .mockResolvedValueOnce(dyingBrowser())
+      .mockResolvedValueOnce(healthyBrowser());
+
+    const { htmlToPdf } = await import("../utils/html-to-pdf");
+    const pdf = await htmlToPdf("<html><body>retry</body></html>");
+
+    expect(Buffer.isBuffer(pdf)).toBe(true);
+    expect(launchMock).toHaveBeenCalledTimes(2);
+  });
+
+  it("does NOT retry a genuine render error on a healthy browser", async () => {
+    const browser = healthyBrowser();
+    browser.newPage = vi.fn(async () => ({
+      setContent: vi.fn(async () => {
+        throw new Error("Render timeout");
+      }),
+      pdf: vi.fn(async () => new Uint8Array()),
+      close: vi.fn(async () => undefined),
+    }));
+    launchMock.mockResolvedValue(browser);
+
+    const { htmlToPdf } = await import("../utils/html-to-pdf");
+    await expect(htmlToPdf("<html></html>")).rejects.toThrow("Render timeout");
+    expect(launchMock).toHaveBeenCalledTimes(1);
+  });
+});