Fix: resolution structs and import aliases to support separated namespaces

doc/architecture.md

@@ -4,4 +4,18 @@ are unnecessary at this stage. Typically, they are used to resolve relative
 paths during import parsing. However, in our architecture, the prefix before
 the first `::` in a `use` statement is always an dependency root path. Since all
 dependency root paths are unique and strictly bound to specific paths, the resolver
-can always unambiguously resolve the path without needing relative pointers.
+can always unambiguously resolve the path without needing relative pointers.
+
+# Architecture Note: Namespace Separation in SimplicityHL
+
+SimplicityHL uses distinct namespaces for types and values. This allows the same identifier to refer to different things depending on where it appears in the code — the compiler determines the correct interpretation from syntactic context, with no risk of collision.
+
+``` Rust
+fn foo() -> bool { false }
+type foo = bool;
+
+fn main() {
+    let x: foo = false; // type namespace  - type alias
+    assert!(foo());     // value namespace - function
+}
+```

src/driver/mod.rs

@@ -136,6 +136,7 @@ pub struct DependencyGraph {
     /// This serves as the exact inverse of the `lookup` map.
     paths: Vec<CanonPath>,
 
+    // TODO: Consider to optimising this with `Vec` instead of `HashMap`
     /// The Adjacency List: Defines the Directed acyclic Graph (DAG) of imports.
     ///
     /// The Key (`usize`) is the ID of a "Parent" module (the file doing the importing).