feat(typedef): re-export schema layer public API from lib.rs

Re-export Endian, VariableEncoding, DiscriminatorKind, and the parse_*
functions plus normalize_refs from the schema module so they're accessible
at the crate root alongside TypedefError.

crates/alknet-typedef/src/lib.rs

@@ -32,3 +32,7 @@ pub mod tunion;
 pub mod validation;
 
 pub use error::TypedefError;
+pub use schema::{
+    parse_align, parse_discriminator, parse_encoding, parse_endian, parse_max_length,
+    normalize_refs, DiscriminatorKind, Endian, VariableEncoding,
+};