diff --git a/apps/web/src/lib/api.ts b/apps/web/src/lib/api.ts
index 2d4731b..8a635e5 100644
--- a/apps/web/src/lib/api.ts
+++ b/apps/web/src/lib/api.ts
@@ -1,15 +1,8 @@
 /**
  * API client utilities for the web app.
- *
- * BUG: imports `useThrottle` from @e2e/utils, but that hook was renamed to
- * `useDebounce`. This causes a TypeScript error and a runtime crash.
- *
- * Fix: change the import to `useDebounce`.
  */
 
-// BUG: useThrottle no longer exists — was renamed to useDebounce
-import { useThrottle } from "@e2e/utils"
-import { formatDate, formatAUD } from "@e2e/utils"
+import { useDebounce, formatDate, formatAUD } from "@e2e/utils"
 
 export const BASE_URL = process.env.API_URL ?? "http://localhost:3000"
 
@@ -28,5 +21,5 @@ export async function fetchPosts() {
 // Re-export formatting utilities used throughout the app
 export { formatDate, formatAUD }
 
-// Re-export the debounce hook (currently broken import)
-export { useThrottle as useSearchDebounce }
+// Re-export the debounce hook
+export { useDebounce as useSearchDebounce }
diff --git a/bunfig.toml b/bunfig.toml
index 3258d71..376bf35 100644
--- a/bunfig.toml
+++ b/bunfig.toml
@@ -1,2 +1,6 @@
+# `environment = "happy-dom"` is a Jest/Vitest concept — Bun has no such [test]
+# option and silently ignores it, which left `document` undefined for the React
+# component tests. Registering happy-dom via a preload script is what actually
+# installs the DOM globals.
 [test]
-environment = "happy-dom"
\ No newline at end of file
+preload = ["./packages/ui/test/setup.ts"]
diff --git a/packages/ui/src/components/Button/Button.tsx b/packages/ui/src/components/Button/Button.tsx
index af65c97..7edc37c 100644
--- a/packages/ui/src/components/Button/Button.tsx
+++ b/packages/ui/src/components/Button/Button.tsx
@@ -14,16 +14,22 @@ type Props = {
   "aria-label"?: string
 }
 
+/**
+ * Fallback accessible name for an icon-only button whose author supplied no
+ * `aria-label`. This is a last-resort floor so the control is never left with no
+ * accessible name at all (WCAG 2.2 AA SC 4.1.2) — it is deliberately generic and
+ * is NOT a substitute for a meaningful label, hence the development warning.
+ */
+const ICON_ONLY_FALLBACK_LABEL = "Button"
+
 /**
  * Button component.
  *
- * BUG: When `iconOnly` is true, the button renders without visible text.
- * An `aria-label` is required for screen reader accessibility (WCAG 2.1 SC 4.1.2),
- * but the component does not enforce or warn about its absence.
- *
- * The test in Button.test.tsx checks that an icon-only button has an accessible name.
- * Fix: throw/warn in development when `iconOnly && !aria-label`, or always render
- * the aria-label attribute when iconOnly is true.
+ * Accessibility: an icon-only button has no visible text, so its accessible name
+ * must come from `aria-label` (WCAG 2.2 AA SC 4.1.2 Name, Role, Value). For
+ * buttons that do render text we leave `aria-label` unset so the visible label
+ * remains the accessible name — overriding it would break SC 2.5.3 (Label in
+ * Name).
  */
 export function Button({
   children,
@@ -34,13 +40,20 @@ export function Button({
   onClick,
   "aria-label": ariaLabel,
 }: Props) {
+  if (process.env.NODE_ENV !== "production" && iconOnly && !ariaLabel) {
+    console.warn(
+      "Button: `iconOnly` buttons have no visible text, so they require an " +
+        "`aria-label` describing the action (WCAG 2.2 AA SC 4.1.2). Falling back " +
+        `to "${ICON_ONLY_FALLBACK_LABEL}", which is not a meaningful label.`,
+    )
+  }
+
   return (
     <button
       className={`btn btn-${variant}`}
       disabled={disabled}
       onClick={onClick}
-      // BUG: aria-label is not applied when iconOnly is true and no ariaLabel is passed
-      // The component should enforce aria-label for icon-only buttons
+      aria-label={ariaLabel ?? (iconOnly ? ICON_ONLY_FALLBACK_LABEL : undefined)}
     >
       {icon && <span className="btn-icon">{icon}</span>}
       {!iconOnly && children}
diff --git a/packages/ui/src/components/DataTable/DataTable.tsx b/packages/ui/src/components/DataTable/DataTable.tsx
index 429a6e3..ad9d192 100644
--- a/packages/ui/src/components/DataTable/DataTable.tsx
+++ b/packages/ui/src/components/DataTable/DataTable.tsx
@@ -15,23 +15,17 @@ type Props<T extends Record<string, unknown>> = {
 
 /**
  * DataTable with client-side sorting.
- *
- * BUG: The sort handler has a stale closure — it captures `sortDir` at the
- * time the handler is created, so toggling sort direction does not work
- * correctly after the first click. The second click always sorts in the same
- * direction as the first.
- *
- * Fix: use the functional form of setState — `setSortDir(prev => ...)` —
- * so the toggle always reads the current value.
  */
 export function DataTable<T extends Record<string, unknown>>({ data, columns }: Props<T>) {
   const [sortKey, setSortKey] = useState<keyof T | null>(null)
   const [sortDir, setSortDir] = useState<SortDir>("asc")
 
-  // BUG: stale closure — sortDir is captured at handler creation time
   const handleSort = (key: keyof T) => {
     if (sortKey === key) {
-      setSortDir(sortDir === "asc" ? "desc" : "asc") // BUG: reads stale sortDir
+      // Functional update: reads the committed value rather than the `sortDir`
+      // captured when this handler was created, so the toggle stays correct even
+      // if two clicks are batched into a single render pass.
+      setSortDir((prev) => (prev === "asc" ? "desc" : "asc"))
     } else {
       setSortKey(key)
       setSortDir("asc")
diff --git a/packages/utils/src/format/date.ts b/packages/utils/src/format/date.ts
index 609e46c..19d687b 100644
--- a/packages/utils/src/format/date.ts
+++ b/packages/utils/src/format/date.ts
@@ -1,21 +1,31 @@
 /**
  * Date formatting utilities.
+ */
+
+/**
+ * Format a date as an Australian-style D/MM/YYYY string (e.g. `15/06/2024`,
+ * `1/03/2024`) in the viewer's local timezone.
  *
- * BUG: formatDate passes `'en-AU'` as the locale but then uses a US-style
- * format string option (`month: 'numeric'` before `day: 'numeric'`), which
- * produces MM/DD/YYYY output instead of DD/MM/YYYY for Australian dates.
- *
- * Fix: use `dateStyle: 'short'` with `'en-AU'` locale, which correctly
- * produces DD/MM/YYYY, or explicitly set `day: 'numeric', month: 'numeric', year: 'numeric'`
- * and rely on the locale to order them correctly.
+ * Note on implementation: ICU normalises `en-AU` to a zero-padded day whenever
+ * explicit field options are supplied, *regardless of the order they are given
+ * in* — so `{ day: 'numeric', month: 'numeric', year: 'numeric' }` still yields
+ * `01/03/2024`. The only option that produces an unpadded day is
+ * `dateStyle: 'short'`, but that also truncates the year to two digits
+ * (`1/3/24`). To get an unpadded day alongside a four-digit year we format to
+ * parts and strip the day's padding ourselves. Do not "simplify" this back to a
+ * plain `format()` call without re-running date.test.ts.
  */
 export function formatDate(date: Date): string {
-  // BUG: explicit field order overrides locale ordering — produces M/D/YYYY not D/M/YYYY
-  return new Intl.DateTimeFormat("en-AU", {
-    month: "numeric",
-    day: "numeric",
+  const parts = new Intl.DateTimeFormat("en-AU", {
+    day: "2-digit",
+    month: "2-digit",
     year: "numeric",
-  }).format(date)
+  }).formatToParts(date)
+
+  const value = (type: Intl.DateTimeFormatPartTypes): string =>
+    parts.find((part) => part.type === type)?.value ?? ""
+
+  return `${Number(value("day"))}/${value("month")}/${value("year")}`
 }
 
 export function formatDateTime(date: Date): string {
diff --git a/tsconfig.json b/tsconfig.json
index 167f910..eb81c6a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -6,6 +6,7 @@
     "jsx": "react-jsx",
     "strict": true,
     "skipLibCheck": true,
+    "types": ["bun-types", "react"],
     "paths": {
       "@e2e/ui": ["./packages/ui/src/index.ts"],
       "@e2e/utils": ["./packages/utils/src/index.ts"]