fix: switch to HashRouter for Capacitor Android compatibility

The primary cause of the white screen in the APK was BrowserRouter.
Capacitor serves files via https://localhost/ and the HTML5 History API
routing (BrowserRouter) fails to resolve routes in this context,
resulting in a blank white page.

Changes:
- Switch BrowserRouter → HashRouter in AppRouter.tsx
- Add DeepLinkHandler component (handles appUrlOpen for Amber callbacks
  and other deep links in native context)
- Fix Amber callback URL builder to use org.skatespots.app:// custom
  scheme when running in Capacitor (so Android fires an intent back into
  the app instead of navigating a browser)
- Fix getSearchParams() in amber.ts to extract query params from hash
  fragment (HashRouter URLs look like /#/amber-callback?event=XXX)
- Fix captureAmberCallback in main.tsx to check hash fragment too
- Remove debug error overlay (no longer needed)

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/AppRouter.tsx

@@ -1,6 +1,7 @@
 import { lazy, Suspense } from "react";
-import { BrowserRouter, Route, Routes } from "react-router-dom";
+import { HashRouter, Route, Routes } from "react-router-dom";
 import { ScrollToTop } from "./components/ScrollToTop";
+import { DeepLinkHandler } from "./components/DeepLinkHandler";
 
 // Eagerly load only the most-visited pages
 import Index from "./pages/Index";
@@ -61,7 +62,8 @@ function PageLoader() {
 
 export function AppRouter() {
   return (
-    <BrowserRouter>
+    <HashRouter>
+      <DeepLinkHandler />
       <ScrollToTop />
       <Suspense fallback={<PageLoader />}>
         <Routes>
@@ -122,7 +124,7 @@ export function AppRouter() {
           <Route path="*" element={<NotFound />} />
         </Routes>
       </Suspense>
-    </BrowserRouter>
+    </HashRouter>
   );
 }
 export default AppRouter;

src/components/DeepLinkHandler.tsx

@@ -0,0 +1,62 @@
+import { useEffect } from 'react';
+import { useNavigate } from 'react-router-dom';
+
+/**
+ * Forwards OS-level deep-link opens into the React Router navigation stack.
+ *
+ * When the OS launches the app via a URL (Amber NIP-55 callback, custom scheme,
+ * or universal link), Capacitor fires an `appUrlOpen` event. This component
+ * listens for it and navigates to the correct in-app route.
+ *
+ * Uses HashRouter compatible path extraction — strips the origin/scheme so
+ * only the pathname+search+hash is passed to navigate().
+ *
+ * Must be rendered inside a Router (so `useNavigate` works).
+ * Safe to render unconditionally — on web it is a no-op.
+ *
+ * Amber deep-link example:
+ *   org.skatespots.app://amber-callback?event=<data>
+ *   → navigates to /amber-callback?event=<data>
+ */
+export function DeepLinkHandler() {
+  const navigate = useNavigate();
+
+  useEffect(() => {
+    // Only run in Capacitor native context
+    const cap = (window as unknown as { Capacitor?: { isNativePlatform?: () => boolean } }).Capacitor;
+    if (!cap?.isNativePlatform?.()) return;
+
+    let removeListener: (() => void) | undefined;
+
+    async function setup() {
+      try {
+        const { App } = await import('@capacitor/app');
+
+        const listener = await App.addListener('appUrlOpen', (event) => {
+          try {
+            const url = new URL(event.url);
+            // Extract path + query + fragment from the deep link URL
+            const path = url.pathname + url.search + url.hash;
+            if (path && path !== '/') {
+              navigate(path, { replace: true });
+            }
+          } catch {
+            // Invalid URL — ignore
+          }
+        });
+
+        removeListener = () => listener.remove();
+      } catch {
+        // @capacitor/app not available (web build without Capacitor installed)
+      }
+    }
+
+    setup();
+
+    return () => {
+      removeListener?.();
+    };
+  }, [navigate]);
+
+  return null;
+}

src/lib/amber.ts

@@ -178,12 +178,34 @@ export function clearAmberLogin(): void {
   localStorage.removeItem(AMBER_LOGIN_KEY);
 }
 
+/**
+ * Extract search params from both the real query string AND the hash fragment.
+ *
+ * With HashRouter the URL looks like:
+ *   https://localhost/#/amber-callback?event=XXXX
+ * In that case `window.location.search` is empty but the params are embedded
+ * inside `window.location.hash` after the path segment.
+ */
+function getSearchParams(): URLSearchParams {
+  // Normal query string (PWA / browser)
+  if (window.location.search) {
+    return new URLSearchParams(window.location.search);
+  }
+  // HashRouter: extract the query string portion from the hash
+  const hash = window.location.hash; // e.g. "#/amber-callback?event=XXX"
+  const qIndex = hash.indexOf('?');
+  if (qIndex !== -1) {
+    return new URLSearchParams(hash.slice(qIndex));
+  }
+  return new URLSearchParams();
+}
+
 /**
  * Check if the current page was opened as an Amber callback.
  * Also checks pre-captured data from main.tsx for PWA resilience.
  */
 export function isAmberCallback(): boolean {
-  const params = new URLSearchParams(window.location.search);
+  const params = getSearchParams();
   if (params.has('event')) return true;
   
   // Check pre-captured data (PWAs might lose URL params during hydration)
@@ -201,7 +223,7 @@ export function isAmberCallback(): boolean {
  * Falls back to pre-captured data from main.tsx.
  */
 export function getAmberCallbackResult(): string | null {
-  const params = new URLSearchParams(window.location.search);
+  const params = getSearchParams();
   const fromUrl = params.get('event');
   
   if (fromUrl) {
@@ -225,10 +247,17 @@ export function getAmberCallbackResult(): string | null {
 
 /**
  * Clean the URL after processing Amber callback.
+ * With HashRouter we replace the hash to remove the query params.
  */
 export function cleanAmberCallbackUrl(): void {
-  const cleanUrl = window.location.origin + window.location.pathname;
+  if (window.location.hash.includes('?')) {
-  window.history.replaceState({}, '', cleanUrl);
+    // HashRouter: strip query from hash fragment
+    const hashPath = window.location.hash.split('?')[0];
+    window.history.replaceState({}, '', window.location.pathname + hashPath);
+  } else {
+    const cleanUrl = window.location.origin + window.location.pathname;
+    window.history.replaceState({}, '', cleanUrl);
+  }
 }
 
 /**
@@ -240,9 +269,22 @@ function generateOperationId(): string {
 
 /**
  * Build the dedicated Amber callback URL.
- * Using a fixed /amber-callback path so Amber always returns to the same place.
+ *
+ * In the Capacitor APK we must use the app's custom URI scheme so Android fires
+ * an intent back into the app (not a browser navigation).
+ * Web/PWA builds use the normal https origin.
+ *
+ * The app ID is `org.skatespots.app` — Capacitor registers this as a URI scheme
+ * automatically via the `appId` in capacitor.config.ts.
  */
 function buildCallbackUrl(): string {
+  const isCapacitor = !!(window as unknown as { Capacitor?: { isNativePlatform?: () => boolean } }).Capacitor?.isNativePlatform?.();
+  if (isCapacitor) {
+    // Use the app's custom scheme so Amber fires the intent back into the APK.
+    // DeepLinkHandler in AppRouter.tsx catches appUrlOpen and navigates to the
+    // correct route inside the HashRouter.
+    return 'org.skatespots.app://amber-callback?event=';
+  }
   return `${window.location.origin}/amber-callback?event=`;
 }
 

src/main.tsx

@@ -33,42 +33,36 @@ import '@fontsource/barlow-condensed/700.css';
  * PWAs can sometimes lose URL parameters during React hydration.
  * This runs BEFORE React renders to capture Amber callback data.
  * We store it in sessionStorage so the AmberCallbackHandler can retrieve it.
+ *
+ * Handles both:
+ *  - Normal query string: ?event=XXX  (PWA / browser)
+ *  - HashRouter fragment: #/amber-callback?event=XXX  (Capacitor APK)
  */
 (function captureAmberCallback() {
-  const params = new URLSearchParams(window.location.search);
+  // Try normal query string first
-  const event = params.get('event');
+  let eventParam = new URLSearchParams(window.location.search).get('event');
 
-  if (event) {
+  // Try hash fragment (HashRouter + Capacitor deep link)
+  if (!eventParam) {
+    const hash = window.location.hash;
+    const qIdx = hash.indexOf('?');
+    if (qIdx !== -1) {
+      eventParam = new URLSearchParams(hash.slice(qIdx)).get('event');
+    }
+  }
+
+  if (eventParam) {
     console.log('[Amber Pre-Check] Detected Amber callback in URL');
-    console.log('[Amber Pre-Check] Full URL:', window.location.href);
-    console.log('[Amber Pre-Check] Event param:', event);
-    
-    // Store the callback data immediately before React can interfere
     try {
-      sessionStorage.setItem('amber_callback_event', event);
+      sessionStorage.setItem('amber_callback_event', eventParam);
       sessionStorage.setItem('amber_callback_url', window.location.href);
       sessionStorage.setItem('amber_callback_timestamp', Date.now().toString());
-      console.log('[Amber Pre-Check] Stored callback data in sessionStorage');
     } catch (e) {
       console.error('[Amber Pre-Check] Failed to store callback:', e);
     }
   }
 })();
 
-// Global error trap — shows error on screen in the APK so we can debug
-// without needing USB/adb. Remove once white screen is fixed.
-window.onerror = (msg, src, line, col, err) => {
-  const div = document.createElement('div');
-  div.style.cssText = 'position:fixed;top:0;left:0;right:0;bottom:0;background:#000;color:#ff0040;padding:16px;font:14px monospace;z-index:99999;overflow:auto;white-space:pre-wrap;word-break:break-all;';
-  div.textContent = `ERROR:\n${msg}\n\n${src}:${line}:${col}\n\n${err?.stack || ''}`;
-  document.body.appendChild(div);
-};
-window.onunhandledrejection = (e) => {
-  const div = document.createElement('div');
-  div.style.cssText = 'position:fixed;top:0;left:0;right:0;bottom:0;background:#000;color:#ff6600;padding:16px;font:14px monospace;z-index:99999;overflow:auto;white-space:pre-wrap;word-break:break-all;';
-  div.textContent = `UNHANDLED REJECTION:\n${e.reason?.stack || e.reason || 'unknown'}`;
-  document.body.appendChild(div);
-};
 
 createRoot(document.getElementById("root")!).render(
   <ErrorBoundary>