Run oxfmt across repo, add format script and docs

Add .oxfmtignore to skip generated bindings and wasm-pack output.
Add npm format script, update DEVELOPMENT.md for Vite+ toolchain,
and format all non-generated files with oxfmt.

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

src-web/lib/capitalize.ts

@@ -1,6 +1,6 @@
 export function capitalize(str: string): string {
   return str
-    .split(' ')
+    .split(" ")
     .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
-    .join(' ');
+    .join(" ");
 }