Conformance: Error code properties (ERR_*) missing from polyfill errors

[NathanFlurry]

Upstream Node.js tests expect errors thrown by built-in modules to have a code property (e.g., ERR_INVALID_ARG_TYPE). Our polyfills throw plain TypeError/RangeError without the code property.

Affected modules: path, assert, buffer, url, querystring, util, fs.

Tracked via conformance test exclusions (category: implementation-gap).

[mustafa-sayyed]

Hey @NathanFlurry,

Would love to work on this issue. Please assign it to me.