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/useShouldFloatSidebar.ts

@@ -1,4 +1,4 @@
-import { useWindowSize } from 'react-use';
+import { useWindowSize } from "react-use";
 
 const WINDOW_FLOATING_SIDEBAR_WIDTH = 600;