feat: Add component strucutre for calls and super basic livekit implementation

packages/call/src/screen.tsx

@@ -1,3 +1,16 @@
+import { useCall } from "./context";
+
+import MainLayout from "./views/main/layout";
+import MainGrid from "./views/main/grid";
+import MainFocused from "./views/main/focused";
+import Preview from "./views/preview";
+
 export default function Screen() {
-  return <div></div>;
+  const { view } = useCall();
+
+  return view === "preview" ? (
+    <Preview />
+  ) : (
+    <MainLayout>{view === "grid" ? <MainGrid /> : <MainFocused />}</MainLayout>
+  );
 }