Stdlib First

Reuse-before-build discipline for writing NEW TypeScript/Node or C#/.NET code. Trigger at two decision moments: (1) about to write a new function, utility, helper, wrapper, service, or algorithm in TS or C# — "write a helper to X", "implement retry / date-parsing / validation logic", "create a service/module for Y"; (2) adding or choosing a dependency — "should we add lodash/Polly", "which library for X". Walks a strict reuse ladder — built-in/standard library first, then (C#) first-party Microsoft.Extensions.*, then a library the project already uses, custom code last — plus precise types, specific error classes, and doc comments; always asks before adding a new package.…