[features] Make HTTP/1 serving a required dependency #116

Problem

Gotcha exposes an optional http1 feature left over from Cloudflare Worker support. With that integration gone, HTTP/1 serving is a required capability. The old feature wiring lets downstream applications disable a dependency that the unconditional startup implementation requires.

A standalone consumer on main 17633f39eb40719db8636b13838c8a0c580c275d cannot compile this dependency:

[dependencies]
gotcha = { path = "/path/to/gotcha/gotcha", default-features = false, features = ["openapi"] }

cargo check fails with error[E0425]: cannot find function serve in crate axum in gotcha/src/startup.rs. Workspace feature unification can mask the problem.

Required behavior

The maintainer clarified that the switch existed for Cloudflare Worker integration, which is no longer supported. HTTP/1 must always be enabled. The earlier proposal to hide startup APIs behind http1 was rejected.

• Enable Axum's http1 and tokio directly on the dependency and remove gotcha's obsolete http1 feature.
• Keep Gotcha::run, listen, listen_on, and GotchaApp::run available with any feature configuration, including default-features = false.
• Remove explicit http1 selections from examples and the special case in the feature matrix. Document that downstream consumers must remove "http1" from their feature lists.
• Verify the four startup entry points in a standalone consumer with defaults disabled, with and without openapi. Run existing serving tests without default features.

Optional OpenAPI, metrics, CORS, static files, and task support stay optional. Schema-only libraries can continue to use gotcha_core without introducing gotcha's web dependencies.

Implementation

PR #118 implements this required HTTP/1 dependency model at bc2838b0a5443a3484713aab6a292601cc3609ae. The framework startup implementation remains unchanged from main.

Local standalone consumer checks, gotcha tests/doctests (defaults disabled and all features), workspace Clippy, formatting, and documentation builds all passed. All 11 Rust CI checks also passed. The PR remains open for maintainer review and merge.