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>

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: voidzero-dev/setup-vp@v1
         with:
-          node-version: '24'
+          node-version: "24"
           cache: true
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@v2