test(web): add 23 edge-case tests across UI components and lib utils

Covers: aria-sort/aria-labelledby attributes, non-Error throws in
ErrorBoundary, NaN/MAX_SAFE_INTEGER in formatCents, invalid dates,
carriage returns in CSV, self-closing HTML tags in sanitize, non-digit
input in DateInput, panel-click-not-dismissing in ConfirmDialog,
role="search" on FilterBar.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/components/ui/ErrorBoundary.test.tsx

@@ -183,6 +183,22 @@ describe("ErrorBoundary", () => {
   });
 });
 
+describe("edge cases", () => {
+  it("catches a thrown string (non-Error object)", () => {
+    function ThrowString(): React.ReactNode {
+      throw "string error";
+    }
+    const spy = vi.spyOn(console, "error").mockImplementation(() => {});
+    render(
+      <ErrorBoundary>
+        <ThrowString />
+      </ErrorBoundary>,
+    );
+    expect(screen.getByText(/something went wrong/i)).toBeInTheDocument();
+    spy.mockRestore();
+  });
+});
+
 describe("DefaultErrorFallback", () => {
   it("renders the heading", () => {
     render(<DefaultErrorFallback error={new Error("Boom")} reset={vi.fn()} />);