Fetch: crate root forbids unsafe and denies panicking lints, like every other crate

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/fetch/src/lib.rs

@@ -16,6 +16,8 @@
 //! Native only: on wasm32 this crate is empty (the web build downloads no models).
 
 #![cfg(not(target_arch = "wasm32"))]
+#![forbid(unsafe_code)]
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 
 pub mod http;