Function generate_e2e 

pub fn generate_e2e(
    config: &ResolvedCrateConfig,
    e2e_config: &E2eConfig,
    languages: Option<&[String]>,
    type_defs: &[TypeDef],
) -> Result<Vec<GeneratedFile>>

Generate e2e test projects from fixtures.

Returns the list of generated files. The caller is responsible for writing them to disk.

type_defs is the IR type registry for the source crate. Pass &api.types from the extracted alef_core::ir::ApiSurface. It is forwarded to generators that need to introspect struct field types (e.g. the TypeScript/WASM backend uses it to auto-derive nested_types for wasm-bindgen class wrapping). Pass an empty slice when the registry is not available; generators will fall back to explicit call-override mappings.