fix(game): own export chooser modal; PNG option outside in-app webviews only

Telegram's native showPopup delivers its callback with no user
activation, so navigator.share (TG iOS) and clipboard writes (TG
Android GCG copy) silently fail from it — the chooser is now always the
app's own modal, keeping the button click's gesture alive for the
delivery APIs.

The data:URL preview modal is dropped: the Android TG/VK long-press
menu mangles data: URLs (dead download, black-screen open, base64
clipboard garbage), so a binary PNG has no working client-side route in
those webviews at all. The image option is withheld there until the
server-rendered signed-URL delivery (Telegram downloadFile /
VKWebAppDownloadFile) lands; the plain web and mobile browsers keep it.

On-device findings by the owner on the test contour (TG iOS, TG
Android, VK Android).

ui/src/lib/share.ts

@@ -81,19 +81,14 @@ function downloadFile(content: Blob | string, filename: string, type = 'applicat
 }
 
 /**
- * pickImageDelivery decides how to deliver the PNG game image. Web Share (with the file) wins
- * wherever it exists — mobile browsers and the iOS Telegram Mini App; a plain desktop browser
- * downloads the Blob. The remaining webviews (Android Telegram/VK, the desktop VK iframe) can
- * neither share a file nor honour <a download>, and unlike the tiny GCG text a binary PNG has
- * no clipboard-text fallback — there the caller shows the image in a preview modal ('preview')
- * for a long-press/right-click save, with a clipboard-image copy where supported. Pure, so it
- * is unit-tested with a mock navigator.
+ * pickImageDelivery decides how to deliver the PNG game image: Web Share (with the file)
+ * wherever it exists — mobile browsers and the iOS Telegram Mini App — else a Blob download.
+ * The image option is not offered inside the in-app WebViews at all (Android Telegram/VK, the
+ * desktop VK iframe): a binary PNG has no working route there until the server-rendered
+ * signed-URL delivery lands, so this decision never sees them. Pure, unit-tested with a mock
+ * navigator.
  */
-export function pickImageDelivery(
-  nav: ShareNav | undefined,
-  file: File,
-  inAppWebView: boolean,
-): 'share' | 'download' | 'preview' {
+export function pickImageDelivery(nav: ShareNav | undefined, file: File): 'share' | 'download' {
   if (
     nav &&
     typeof nav.canShare === 'function' &&
@@ -102,23 +97,18 @@ export function pickImageDelivery(
   ) {
     return 'share';
   }
-  return inAppWebView ? 'preview' : 'download';
+  return 'download';
 }
 
 /**
- * shareOrDownloadImage delivers the rendered game image by the best available route and reports
- * which it took — 'shared', 'downloaded' or 'preview' (the caller opens its preview modal). The
- * Web Share invariant matches shareOrDownloadGcg: a cancelled or failed share is a deliberate
- * no-op, never a Blob-download fallback (an <a download> strands the iOS WKWebView on the blob:
- * URL).
+ * shareOrDownloadImage delivers the rendered game image and reports the route taken. The Web
+ * Share invariant matches shareOrDownloadGcg: a cancelled or failed share is a deliberate
+ * no-op, never a Blob-download fallback (an <a download> strands the iOS WKWebView on the
+ * blob: URL).
  */
-export async function shareOrDownloadImage(
-  file: File,
-  inAppWebView: boolean,
-): Promise<'shared' | 'downloaded' | 'preview'> {
+export async function shareOrDownloadImage(file: File): Promise<'shared' | 'downloaded'> {
   const nav = typeof navigator !== 'undefined' ? navigator : undefined;
-  const decision = pickImageDelivery(nav, file, inAppWebView);
-  if (decision === 'share' && nav) {
+  if (pickImageDelivery(nav, file) === 'share' && nav) {
     try {
       await nav.share({ files: [file], title: file.name });
     } catch {
@@ -126,40 +116,8 @@ export async function shareOrDownloadImage(
     }
     return 'shared';
   }
-  if (decision === 'download') downloadFile(file, file.name, file.type);
-  return decision === 'download' ? 'downloaded' : 'preview';
-}
-
-/** canCopyImage reports whether the clipboard-image API (ClipboardItem) is available, so the
- *  preview modal offers a copy button only where it can work. */
-export function canCopyImage(): boolean {
-  return (
-    typeof navigator !== 'undefined' &&
-    typeof ClipboardItem !== 'undefined' &&
-    typeof navigator.clipboard?.write === 'function'
-  );
-}
-
-/** copyImageToClipboard writes the PNG blob to the system clipboard (where canCopyImage). */
-export async function copyImageToClipboard(blob: Blob): Promise<boolean> {
-  if (!canCopyImage()) return false;
-  try {
-    await navigator.clipboard.write([new ClipboardItem({ [blob.type]: blob })]);
-    return true;
-  } catch {
-    return false;
-  }
-}
-
-/** blobToDataURL inlines a blob as a data: URL — the preview modal's <img> source (a data URL
- *  survives long-press "save image" in webviews where a blob: URL may not). */
-export function blobToDataURL(blob: Blob): Promise<string> {
-  return new Promise((resolve, reject) => {
-    const r = new FileReader();
-    r.onload = () => resolve(String(r.result));
-    r.onerror = () => reject(r.error ?? new Error('blobToDataURL failed'));
-    r.readAsDataURL(blob);
-  });
+  downloadFile(file, file.name, file.type);
+  return 'downloaded';
 }
 
 type TextShareNav = Pick<Navigator, 'share'> & { canShare?: Navigator['canShare'] };