Expose Git SHA to window (#1847)

* expose git sha

* move to global.d.ts

* fix vercel domain

src/global.d.ts

 
 interface Window {
   ClipboardItem: any;
+  __EXCALIDRAW_SHA__: string;
 }
 
 interface Clipboard extends EventTarget {

src/index.tsx

 
 const SentryEnvHostnameMap: { [key: string]: string } = {
   "excalidraw.com": "production",
-  "now.sh": "staging",
+  "vercel.app": "staging",
 };
 
+const REACT_APP_DISABLE_SENTRY =
+  process.env.REACT_APP_DISABLE_SENTRY === "true";
+const REACT_APP_GIT_SHA = process.env.REACT_APP_GIT_SHA as string;
+
 // Disable Sentry locally or inside the Docker to avoid noise/respect privacy
 const onlineEnv =
-  process.env.REACT_APP_DISABLE_SENTRY !== "true" &&
+  !REACT_APP_DISABLE_SENTRY &&
   Object.keys(SentryEnvHostnameMap).find(
     (item) => window.location.hostname.indexOf(item) >= 0,
   );
     ? "https://7bfc596a5bf945eda6b660d3015a5460@sentry.io/5179260"
     : undefined,
   environment: onlineEnv ? SentryEnvHostnameMap[onlineEnv] : undefined,
-  release: process.env.REACT_APP_GIT_SHA,
+  release: REACT_APP_GIT_SHA,
   ignoreErrors: [
     "undefined is not an object (evaluating 'window.__pad.performLoop')", // Only happens on Safari, but spams our servers. Doesn't break anything
   ],
   ],
 });
 
+window.__EXCALIDRAW_SHA__ = REACT_APP_GIT_SHA;
+
 // Block pinch-zooming on iOS outside of the content area
 document.addEventListener(
   "touchmove",