diff --git a/apps/web/src/lib/api.ts b/apps/web/src/lib/api.ts
index 2d4731b..ac91c59 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 under the app's domain-specific name
+export { useDebounce as useSearchDebounce }
diff --git a/bunfig.toml b/bunfig.toml
index 3258d71..0b64f7c 100644
--- a/bunfig.toml
+++ b/bunfig.toml
@@ -1,2 +1,2 @@
 [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..fb952ba 100644
--- a/packages/ui/src/components/Button/Button.tsx
+++ b/packages/ui/src/components/Button/Button.tsx
@@ -14,16 +14,23 @@ type Props = {
   "aria-label"?: string
 }
 
+const FALLBACK_ICON_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.
+ * An icon-only button has no visible text, so it must carry an `aria-label` to
+ * expose an accessible name to assistive technology (WCAG 2.2 SC 4.1.2
+ * Name, Role, Value).
+ *
+ * An explicitly passed `aria-label` is always forwarded, whether or not the
+ * button is icon-only. A button with visible text derives its accessible name
+ * from its content by default, so when a caller overrides that name it must
+ * keep the visible text within the label (WCAG 2.2 SC 2.5.3 Label in Name).
  *
- * 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.
+ * If `iconOnly` is set without an `aria-label`, the component falls back to any
+ * string children and then to a generic label so the button is never left
+ * unnamed, and warns in development so the omission is caught early.
  */
 export function Button({
   children,
@@ -34,13 +41,26 @@ export function Button({
   onClick,
   "aria-label": ariaLabel,
 }: Props) {
+  let accessibleName: string | undefined = ariaLabel?.trim() || undefined
+
+  if (iconOnly) {
+    const childText = typeof children === "string" ? children.trim() : ""
+    accessibleName = ariaLabel?.trim() || childText || FALLBACK_ICON_LABEL
+
+    if (process.env.NODE_ENV !== "production" && !ariaLabel?.trim()) {
+      console.warn(
+        "[Button] `iconOnly` buttons require an explicit `aria-label` to provide an " +
+          `accessible name (WCAG 2.2 SC 4.1.2). Falling back to "${accessibleName}".`,
+      )
+    }
+  }
+
   return (
     <button
       className={`btn btn-${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={accessibleName}
     >
       {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..20f6db6 100644
--- a/packages/ui/src/components/DataTable/DataTable.tsx
+++ b/packages/ui/src/components/DataTable/DataTable.tsx
@@ -16,26 +16,24 @@ 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.
+ * Sort key and direction are held in a single state object and updated through
+ * the functional form of `setState`, so the direction toggle always reads the
+ * current committed value rather than the value captured when the click handler
+ * was created.
  */
 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")
+  const [sort, setSort] = useState<{ key: keyof T | null; dir: SortDir }>({
+    key: null,
+    dir: "asc",
+  })
+  const { key: sortKey, dir: sortDir } = sort
 
-  // 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
-    } else {
-      setSortKey(key)
-      setSortDir("asc")
-    }
+    setSort((prev) =>
+      prev.key === key
+        ? { key, dir: prev.dir === "asc" ? "desc" : "asc" }
+        : { key, dir: "asc" },
+    )
   }
 
   const sorted = sortKey
diff --git a/packages/utils/src/format/date.ts b/packages/utils/src/format/date.ts
index 609e46c..79d5f04 100644
--- a/packages/utils/src/format/date.ts
+++ b/packages/utils/src/format/date.ts
@@ -1,21 +1,27 @@
 /**
  * Date formatting utilities.
  *
- * 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.
+ * Australian date convention is day-before-month. `formatDate` produces
+ * `d/MM/yyyy` (e.g. `1/03/2024`, `15/06/2024`).
  *
- * 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: the ICU data for `en-AU` resolves `day: 'numeric'` to a zero-padded
+ * 2-digit day, so the day part is taken from `formatToParts` with any leading
+ * zero stripped rather than relying on the locale pattern alone.
  */
+const AU_DATE_FORMAT = new Intl.DateTimeFormat("en-AU", {
+  day: "numeric",
+  month: "2-digit",
+  year: "numeric",
+})
+
 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",
-    year: "numeric",
-  }).format(date)
+  const parts = AU_DATE_FORMAT.formatToParts(date)
+  const part = (type: Intl.DateTimeFormatPartTypes) =>
+    parts.find((p) => p.type === type)?.value ?? ""
+
+  const day = String(Number(part("day")))
+
+  return `${day}/${part("month")}/${part("year")}`
 }
 
 export function formatDateTime(date: Date): string {
diff --git a/tsconfig.json b/tsconfig.json
index 167f910..8e00ae0 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -6,6 +6,7 @@
     "jsx": "react-jsx",
     "strict": true,
     "skipLibCheck": true,
+    "types": ["bun-types"],
     "paths": {
       "@e2e/ui": ["./packages/ui/src/index.ts"],
       "@e2e/utils": ["./packages/utils/src/index.ts"]