Function platform_tls_config 

pub fn platform_tls_config() -> TlsConfig

Shared TLS config for every ureq client so OS/enterprise root CAs are honored (#643). ureq’s default RootCerts::WebPki ignores the system store, so requests fail with UnknownIssuer behind TLS-intercepting corporate proxies. Inject this into a ureq::config::Config::builder().tls_config(platform_tls_config()) at each call site — ureq’s builder scope typestate is private, so a shared builder cannot be returned from a function; the shared piece is this TlsConfig.