fix(dashboard): cancel the compression tab's saved-badge timer on unmount

src/app/(dashboard)/dashboard/settings/components/CompressionSettingsTab.tsx

@@ -237,6 +237,16 @@ export default function CompressionSettingsTab() {
   const savedRef = useRef(config);
   const queuedRef = useRef<SettingsPatch<CompressionConfig>[]>([]);
   const saveQueueRef = useRef(Promise.resolve());
+  const statusTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  // The "saved" badge clears itself after 2s; a timer that outlives the tab fires into an
+  // unmounted (or torn-down) React tree.
+  useEffect(
+    () => () => {
+      if (statusTimerRef.current) clearTimeout(statusTimerRef.current);
+    },
+    []
+  );
 
   useEffect(() => {
     fetch("/api/settings/compression")
@@ -301,7 +311,13 @@ export default function CompressionSettingsTab() {
       // A failure stays on screen until the next edit, so a queued success or an earlier
       // save's timeout cannot hide a field that just rolled back.
       setStatus((shown) => (ok ? (shown === "error" ? shown : "saved") : "error"));
-      if (ok) setTimeout(() => setStatus((shown) => (shown === "saved" ? "" : shown)), 2000);
+      if (ok) {
+        if (statusTimerRef.current) clearTimeout(statusTimerRef.current);
+        statusTimerRef.current = setTimeout(
+          () => setStatus((shown) => (shown === "saved" ? "" : shown)),
+          2000
+        );
+      }
     });
   };
 

tests/unit/ui/compression-settings-tab-partial-save.test.tsx

@@ -138,11 +138,37 @@ async function renderTab() {
 }
 
 afterEach(() => {
+  vi.restoreAllMocks();
   vi.useRealTimers();
   vi.unstubAllGlobals();
 });
 
 describe("CompressionSettingsTab saves only what changed", () => {
+  it("clears the saved-badge timer when the tab unmounts", async () => {
+    startServer();
+    const nativeSetTimeout = globalThis.setTimeout;
+    const badgeTimers: unknown[] = [];
+    vi.spyOn(globalThis, "setTimeout").mockImplementation(((
+      fn: TimerHandler,
+      ms?: number,
+      ...args: unknown[]
+    ) => {
+      const id = nativeSetTimeout(fn as () => void, ms, ...(args as []));
+      if (ms === 2000) badgeTimers.push(id);
+      return id;
+    }) as typeof setTimeout);
+    const clearSpy = vi.spyOn(globalThis, "clearTimeout");
+
+    const view = render(<CompressionSettingsTab />);
+    await settle();
+    fireEvent.change(inputFor("compressionCacheTTL"), { target: { value: "10" } });
+    await settle();
+    expect(badgeTimers).toHaveLength(1);
+
+    view.unmount();
+    expect(clearSpy).toHaveBeenCalledWith(badgeTimers[0]);
+  });
+
   // Rendering the whole caveman page takes over 5 seconds on a cold run.
   it(
     "keeps Auto-Clarity off on the caveman page when the embedded tab saves",