Refactor: Implement Record Layouts and Optimized Field Access

Introduces a new `RecordLayout` system for efficient and type-safe
record handling.

Key changes:
- `RecordLayout` struct with `O(1)` field lookup using FMap
  optimization.
- Field accessors (`.name`) are now first-class callable values.
- Parser recognizes dot-prefixed identifiers as field accessors.
- Binder and TypeChecker handle field accessors.
- Optimizer transforms field accessor calls into specialized `GetField`
  nodes.
- VM executes `GetField` efficiently by directly accessing record
  values.
- Adds a new `records.myc` example showcasing record features.
- Improves comparison logic for records to use pointer equality for
  layout.

src/ast/compiler/bound_nodes.rs

@@ -97,6 +97,15 @@ pub enum BoundKind<T = ()> {
         captured_by: Vec<Identity>,
     },
 
+    /// A first-class field accessor (e.g. .name)
+    FieldAccessor(crate::ast::types::Keyword),
+
+    /// Specialized field access (O(1) via RecordLayout)
+    GetField {
+        rec: Box<BoundNode<T>>,
+        field: crate::ast::types::Keyword,
+    },
+
     If {
         cond: Box<BoundNode<T>>,
         then_br: Box<BoundNode<T>>,
@@ -188,6 +197,10 @@ where
                     captured_by: cb,
                 },
             ) => na == nb && aa == ab && ka == kb && va == vb && ca == cb,
+            (BoundKind::FieldAccessor(a), BoundKind::FieldAccessor(b)) => a == b,
+            (BoundKind::GetField { rec: ra, field: fa }, BoundKind::GetField { rec: rb, field: fb }) => {
+                ra == rb && fa == fb
+            }
             (
                 BoundKind::If {
                     cond: ca,
@@ -273,6 +286,8 @@ impl<T> BoundKind<T> {
                 };
                 format!("DEF_{}({}, {:?})", k_str, name.name, addr)
             }
+            BoundKind::FieldAccessor(k) => format!("FIELD_ACCESSOR(.{})", k.name()),
+            BoundKind::GetField { field, .. } => format!("GET_FIELD(.{})", field.name()),
             BoundKind::If { .. } => "IF".to_string(),
             BoundKind::Destructure { .. } => "DESTRUCTURE".to_string(),
             BoundKind::Lambda {