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/hooks/useRandomKey.ts

@@ -1,5 +1,5 @@
-import { useCallback, useState } from 'react';
-import { generateId } from '../lib/generateId';
+import { useCallback, useState } from "react";
+import { generateId } from "../lib/generateId";
 
 export function useRandomKey(initialValue?: string) {
   const [value, setValue] = useState<string>(initialValue ?? generateId());