Feat: Add Pipe Node

Introduces a new `Pipe` node to the Abstract Syntax Tree (AST).
This node represents a functional composition pattern, allowing
for chaining of operations.

The changes include:
- Defining the `Pipe` variant in `BoundKind` and `UntypedKind`.
- Implementing parsing logic for the `pipe` keyword.
- Adding handling for the `Pipe` node in various compiler passes
  (analyzer, binder, captures, dumper, macros, optimizer, TCO,
  type checker).
- Including a placeholder implementation for `Pipe` execution in the
  VM.
- Updating integration tests to use the new `pipe` syntax.

src/ast/compiler/macros.rs

@@ -152,6 +152,22 @@ impl<E: MacroEvaluator> MacroExpander<E> {
                 })
             }
 
+            UntypedKind::Pipe { inputs, lambda } => {
+                let mut expanded_inputs = Vec::with_capacity(inputs.len());
+                for input in inputs {
+                    expanded_inputs.push(self.expand_recursive(input)?);
+                }
+                let expanded_lambda = Box::new(self.expand_recursive(*lambda)?);
+                Ok(Node {
+                    identity: node.identity,
+                    kind: UntypedKind::Pipe {
+                        inputs: expanded_inputs,
+                        lambda: expanded_lambda,
+                    },
+                    ty: (),
+                })
+            }
+
             UntypedKind::Lambda { params, body } => {
                 self.registry.push();
                 let expanded_params = self.expand_recursive(*params)?;
@@ -498,6 +514,22 @@ impl<E: MacroEvaluator> MacroExpander<E> {
                 })
             }
 
+            UntypedKind::Pipe { inputs, lambda } => {
+                let mut expanded_inputs = Vec::with_capacity(inputs.len());
+                for input in inputs {
+                    expanded_inputs.push(self.expand_template(input, state)?);
+                }
+                let expanded_lambda = Box::new(self.expand_template(*lambda, state)?);
+                Ok(Node {
+                    identity: node.identity,
+                    kind: UntypedKind::Pipe {
+                        inputs: expanded_inputs,
+                        lambda: expanded_lambda,
+                    },
+                    ty: (),
+                })
+            }
+
             UntypedKind::Lambda { params, body } => {
                 let expanded_params = self.expand_template(*params, state)?;
                 let body = self.expand_template(Node::clone(&body), state)?;