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>

npm/cli-linux-x64/package.json

@@ -5,6 +5,10 @@
     "type": "git",
     "url": "git+https://github.com/mountain-loop/yaak.git"
   },
-  "os": ["linux"],
-  "cpu": ["x64"]
+  "os": [
+    "linux"
+  ],
+  "cpu": [
+    "x64"
+  ]
 }