Twelve factor webapp crate

twelve is a support crate for creating twelve-factor webapps with axum.

Warning: Parts of this crate are still exploratory. Expect substantial API breakage between major versions.

Features

• shutdown_signal() - Graceful shutdown handler for SIGTERM/SIGINT/SIGQUIT
• RequestContext - Axum extractor for reverse proxy X-Script-Name header
• page::ErrorPage - HTML error page rendering with error chain display
• page::AppError - Trait for mapping errors to HTTP status codes
• page::RedirectOnSuccess - POST-Redirect-GET pattern helper

Removed features

• (0.2) util::graceful_shutdown: Moved to twelve::shutdown_signal().
• (0.2) util::as_opt_str: Replace with Option::as_deref() (stable since Rust 1.40).
• (0.2) from_env(): Call envy::from_env() directly.
• (0.2) page::Page: Use maud::Markup directly (enable maud's axum feature).
• (0.2) AppBuilder: Too opinionated. Copy the pattern if needed.
• (0.2) widgets: Empty module removed.