Remove old CRA index.html and fix formatting

- Remove public/index.html (old CRA version, now using root index.html)
- Fix prettier formatting in src/lz-string.d.ts

Vite requires index.html at the project root, not in public/.
The public/ folder is still used for static assets:
- favicon.ico
- logo192.png, logo512.png
- manifest.json
- robots.txt
- favicon/ directory

All Makefile commands verified to pass:
- make lint ✓
- make ci (test-coverage + build + lint) ✓

Author: claude

public/index.html

@@ -1,12 +1,16 @@
-declare module 'lz-string' {
+declare module "lz-string" {
   export function compress(input: string): string;
   export function decompress(compressed: string): string | null;
   export function compressToBase64(input: string): string;
   export function decompressFromBase64(compressed: string): string | null;
   export function compressToUTF16(input: string): string;
   export function decompressFromUTF16(compressed: string): string | null;
   export function compressToUint8Array(input: string): Uint8Array;
-  export function decompressFromUint8Array(compressed: Uint8Array): string | null;
+  export function decompressFromUint8Array(
+    compressed: Uint8Array
+  ): string | null;
   export function compressToEncodedURIComponent(input: string): string;
-  export function decompressFromEncodedURIComponent(compressed: string): string | null;
+  export function decompressFromEncodedURIComponent(
+    compressed: string
+  ): string | null;
 }