feat(frontend): persist filter state across page reloads (#189)

* feat(frontend): persist filter state across page reloads

Add useLocalStorageState hook to persist filter/search state in
forward, node, tunnel, user, and limit pages. Reset filter clears
the persisted value from localStorage.

* feat(ui): add collapsible sidebar and smooth animations

vite-frontend/src/hooks/use-local-storage-state.ts

@@ -0,0 +1,51 @@
+import { useCallback, useState, type SetStateAction } from "react";
+
+const readStoredValue = <T>(key: string, fallbackValue: T): T => {
+  try {
+    const rawValue = localStorage.getItem(key);
+
+    if (rawValue === null) {
+      return fallbackValue;
+    }
+
+    return JSON.parse(rawValue) as T;
+  } catch {
+    return fallbackValue;
+  }
+};
+
+export const useLocalStorageState = <T>(
+  key: string,
+  initialValue: T,
+): readonly [T, (value: SetStateAction<T>) => void, () => void] => {
+  const [value, setValue] = useState<T>(() =>
+    readStoredValue(key, initialValue),
+  );
+
+  const setPersistedValue = useCallback(
+    (nextValue: SetStateAction<T>) => {
+      setValue((prevValue) => {
+        const resolvedValue =
+          typeof nextValue === "function"
+            ? (nextValue as (value: T) => T)(prevValue)
+            : nextValue;
+
+        try {
+          localStorage.setItem(key, JSON.stringify(resolvedValue));
+        } catch {}
+
+        return resolvedValue;
+      });
+    },
+    [key],
+  );
+
+  const resetPersistedValue = useCallback(() => {
+    setValue(initialValue);
+    try {
+      localStorage.removeItem(key);
+    } catch {}
+  }, [initialValue, key]);
+
+  return [value, setPersistedValue, resetPersistedValue] as const;
+};