chore: Move to Typescript (#2783)

This PR moves the entire project to Typescript. Due to the ~1000 ignores this will lead to a messy codebase for a while, but the churn is worth it – all of those ignore comments are places that were never type-safe previously.

closes #1282

app/components/Sidebar/components/DropCursor.tsx

@@ -0,0 +1,40 @@
+import * as React from "react";
+import styled from "styled-components";
+
+function DropCursor({
+  isActiveDrop,
+  innerRef,
+  from,
+}: {
+  isActiveDrop: boolean;
+  innerRef: React.Ref<HTMLDivElement>;
+  from?: string;
+}) {
+  return <Cursor isOver={isActiveDrop} ref={innerRef} from={from} />;
+}
+
+// transparent hover zone with a thin visible band vertically centered
+const Cursor = styled.div<{ isOver?: boolean; from?: string }>`
+  opacity: ${(props) => (props.isOver ? 1 : 0)};
+  transition: opacity 150ms;
+
+  position: absolute;
+  z-index: 1;
+
+  width: 100%;
+  height: 14px;
+  ${(props) => (props.from === "collections" ? "top: 25px;" : "bottom: -7px;")}
+  background: transparent;
+
+  ::after {
+    background: ${(props) => props.theme.slateDark};
+    position: absolute;
+    top: 6px;
+    content: "";
+    height: 2px;
+    border-radius: 2px;
+    width: 100%;
+  }
+`;
+
+export default DropCursor;