Mobile: preserve query params on deep links so email/QR tokens aren't dropped

Universal/app links for the whole couchers.org domain open in-app, but the
catch-all route rebuilt the path from slug segments only and silently dropped
the query string, so token-bearing links (account deletion confirmation,
recovery, unsubscribe, postal verification, strong verification) couldn't
complete. Forward the query string through the catch-all and add dedicated
top-level routes for the links that must work while logged out.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: aapeliv

app/mobile/app/(tabs)/[...slug].tsx

@@ -4,7 +4,7 @@ import WebEmbed from "@/components/WebEmbed";
 import { detailRouteOriginRef } from "@/state/webViewState";
 
 export default function CatchAllScreen() {
-  const { slug } = useLocalSearchParams<{ slug?: string[] }>();
+  const { slug, ...rest } = useLocalSearchParams<{ slug?: string[] }>();
   const router = useRouter();
 
   // slug is undefined/empty when nav state is restored without a valid path
@@ -14,7 +14,17 @@ export default function CatchAllScreen() {
     return <Redirect href="/(tabs)/dashboard" />;
   }
 
-  const path = `/${slug.join("/")}`;
+  // Forward query params the deep link carried (e.g. ?token=, ?code=); the slug
+  // segments only cover the path, so without this they'd be silently dropped.
+  const query = rest as Record<string, string | string[]>;
+  const queryString = Object.entries(query)
+    .flatMap(([key, value]) =>
+      (Array.isArray(value) ? value : [value]).map(
+        (v) => `${encodeURIComponent(key)}=${encodeURIComponent(v)}`,
+      ),
+    )
+    .join("&");
+  const path = `/${slug.join("/")}${queryString ? `?${queryString}` : ""}`;
   return (
     <WebEmbed
       key={path}

app/mobile/app/delete-account.tsx

@@ -0,0 +1,12 @@
+import { useLocalSearchParams } from "expo-router";
+
+import WebEmbed from "@/components/WebEmbed";
+
+export default function DeleteAccountScreen() {
+  const { token } = useLocalSearchParams<{ token?: string }>();
+  const path = token
+    ? `/delete-account?token=${encodeURIComponent(token)}`
+    : "/delete-account";
+
+  return <WebEmbed path={path} />;
+}

app/mobile/app/quick-link.tsx

@@ -0,0 +1,16 @@
+import { useLocalSearchParams } from "expo-router";
+
+import WebEmbed from "@/components/WebEmbed";
+
+export default function QuickLinkScreen() {
+  const { payload, sig } = useLocalSearchParams<{
+    payload?: string;
+    sig?: string;
+  }>();
+  const path =
+    payload && sig
+      ? `/quick-link?payload=${encodeURIComponent(payload)}&sig=${encodeURIComponent(sig)}`
+      : "/quick-link";
+
+  return <WebEmbed path={path} />;
+}

app/mobile/app/recover-account.tsx

@@ -0,0 +1,12 @@
+import { useLocalSearchParams } from "expo-router";
+
+import WebEmbed from "@/components/WebEmbed";
+
+export default function RecoverAccountScreen() {
+  const { token } = useLocalSearchParams<{ token?: string }>();
+  const path = token
+    ? `/recover-account?token=${encodeURIComponent(token)}`
+    : "/recover-account";
+
+  return <WebEmbed path={path} />;
+}

app/mobile/app/verify-postal.tsx

@@ -0,0 +1,12 @@
+import { useLocalSearchParams } from "expo-router";
+
+import WebEmbed from "@/components/WebEmbed";
+
+export default function VerifyPostalScreen() {
+  const { c } = useLocalSearchParams<{ c?: string }>();
+  const path = c
+    ? `/verify-postal?c=${encodeURIComponent(c)}`
+    : "/verify-postal";
+
+  return <WebEmbed path={path} />;
+}