fix: hydrate wallet state from SecureStore on cold start (fixes #34)

app/index.tsx

@@ -1,8 +1,23 @@
+import { useEffect } from "react";
 import { Redirect } from "expo-router";
+import { View, ActivityIndicator } from "react-native";
 import { useWalletStore } from "@/store/walletStore";
 
 export default function Index() {
-  const { isOnboarded } = useWalletStore();
+  const { isOnboarded, hydrated, hydrate } = useWalletStore();
+
+  useEffect(() => {
+    if (!hydrated) hydrate();
+  }, [hydrated, hydrate]);
+
+  if (!hydrated) {
+    return (
+      <View style={{ flex: 1, backgroundColor: "#0f172a", alignItems: "center", justifyContent: "center" }}>
+        <ActivityIndicator size="large" color="#3b82f6" />
+      </View>
+    );
+  }
+
   return isOnboarded ? (
     <Redirect href="/tabs/home" />
   ) : (

src/store/__tests__/walletStore.test.ts

@@ -0,0 +1,34 @@
+jest.mock("@/services/secureStorage", () => ({
+  getSecretKey: jest.fn(),
+}));
+
+import { getSecretKey } from "@/services/secureStorage";
+import { useWalletStore } from "@/store/walletStore";
+
+const mockedGetSecretKey = getSecretKey as jest.Mock;
+
+beforeEach(() => {
+  useWalletStore.setState({ isOnboarded: false, publicKey: null, balances: {}, hydrated: false });
+  mockedGetSecretKey.mockReset();
+});
+
+describe("walletStore", () => {
+  it("restores onboarded state when a secret exists in SecureStore", async () => {
+    mockedGetSecretKey.mockResolvedValue("SBGELNIUVE6A5I43FCPBKX7ZIO3AO63XPWP5WEQBOE4F6NTK6RNKIG3X");
+    await useWalletStore.getState().hydrate();
+    const state = useWalletStore.getState();
+    expect(state.hydrated).toBe(true);
+    expect(state.isOnboarded).toBe(true);
+    expect(state.publicKey).toBeTruthy();
+    expect(state.publicKey).toMatch(/^G[A-Z0-9]{55}$/);
+  });
+
+  it("leaves isOnboarded false when no secret exists", async () => {
+    mockedGetSecretKey.mockResolvedValue(null);
+    await useWalletStore.getState().hydrate();
+    const state = useWalletStore.getState();
+    expect(state.hydrated).toBe(true);
+    expect(state.isOnboarded).toBe(false);
+    expect(state.publicKey).toBeNull();
+  });
+});