feat(mobile): improve image viewer and install entry

(cherry picked from commit 556bfd2919)

src/app/chat/chat-screen.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useEffect, useMemo, type CSSProperties } from "react";
+import { useEffect, useMemo, useRef, type CSSProperties } from "react";
 import Image from "next/image";
 import { useRouter, useSearchParams } from "next/navigation";
 
@@ -70,6 +70,8 @@ export function ChatScreen() {
   const chatDispatch = useChatDispatch();
   const authState = useAuthState();
   const authDispatch = useAuthDispatch();
+  const imageOpenedFromChatRef = useRef(false);
+  const imageViewerClosingRef = useRef(false);
   useSplashLatestMessageSync({
     characterId: state.characterId,
     historyLoaded: state.historyLoaded,
@@ -127,6 +129,13 @@ export function ChatScreen() {
     loginStatus: authState.loginStatus,
   });
 
+  useEffect(() => {
+    if (!imageMessageId) {
+      imageOpenedFromChatRef.current = false;
+      imageViewerClosingRef.current = false;
+    }
+  }, [imageMessageId]);
+
   useEffect(() => {
     if (
       !imageMessageId ||
@@ -218,6 +227,7 @@ export function ChatScreen() {
   }
 
   function handleOpenImage(displayMessageId: string): void {
+    imageOpenedFromChatRef.current = true;
     router.push(
       buildChatImageOverlayUrl(displayMessageId, characterRoutes.chat),
       { scroll: false },
@@ -225,6 +235,13 @@ export function ChatScreen() {
   }
 
   function handleCloseImageViewer(): void {
+    if (imageViewerClosingRef.current) return;
+    imageViewerClosingRef.current = true;
+    if (imageOpenedFromChatRef.current) {
+      imageOpenedFromChatRef.current = false;
+      router.back();
+      return;
+    }
     router.replace(
       buildChatWithoutImageOverlayUrl(searchParams, characterRoutes.chat),
       { scroll: false },