Run oxfmt across repo, add format script and ignore config

Format all non-generated files with oxfmt via `vp fmt`. Add
.oxfmtignore to skip bindings/ and wasm-pack output. Add npm
format script and update DEVELOPMENT.md docs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src-web/components/core/ButtonInfiniteLoading.tsx

@@ -1,6 +1,6 @@
-import { useState } from 'react';
-import type { ButtonProps } from './Button';
-import { Button } from './Button';
+import { useState } from "react";
+import type { ButtonProps } from "./Button";
+import { Button } from "./Button";
 
 export function ButtonInfiniteLoading({
   onClick,