stdx

Use Rust's extended standard library (stdx) — a monorepo of zero-external-dependency crates for supply-chain security. Covers base64, crypto, csv, dotenv, anyerr, singleflight, templates, networking, and more. Import directly from git; never use crates.io equivalents when stdx provides a replacement. Use when writing Rust code that needs encoding, crypto, error handling, config, concurrency, serialization, or common infrastructure.