Function wrap_user_comp_shader 

pub fn wrap_user_comp_shader(translated_body: &str) -> String

Wrap a translated WGSL fragment body into a complete shader module (prelude + texture bindings + entry points).

The user body is pasted into fs_main after standard MD2 inputs (uv, uv_orig, rad, ang, ret) have been declared as locals. The fragment returns vec4<f32>(ret * uniforms.gamma_adj, 1.0), so a well-behaved MD2 shader that assigns to ret produces a correct result.

Made pub so tests and the CLI can inspect the wrapped output before shipping it to naga.