Refactor: Move compiler node definitions to src/ast/nodes

The `bound_nodes.rs` file has been removed and its contents have been
moved to `src/ast/nodes.rs`. This consolidates all AST node definitions
into a single module, improving organization and maintainability.

The `compiler` modules now import these definitions from
`crate::ast::nodes` instead of `crate::ast::compiler::bound_nodes`.

src/ast/environment.rs

@@ -9,7 +9,7 @@ use std::collections::{HashMap, HashSet};
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
-use crate::ast::compiler::bound_nodes::{
+use crate::ast::nodes::{
     Address, AnalyzedNode, ExecNode, GlobalAnalyzedRegistry, GlobalFunctionRegistry, GlobalIdx,
     LambdaBinding, Node, NodeKind, VirtualId,
 };
@@ -93,7 +93,7 @@ struct EnvFunctionRegistry {
 }
 
 impl FunctionRegistry for EnvFunctionRegistry {
-    fn resolve(&self, addr: Address<VirtualId>) -> Option<Rc<Node<crate::ast::compiler::bound_nodes::AnalyzedPhase>>> {
+    fn resolve(&self, addr: Address<VirtualId>) -> Option<Rc<Node<crate::ast::nodes::AnalyzedPhase>>> {
         if let Address::Global(idx) = addr {
             self.analyzed_registry.borrow().get(&idx).cloned()
         } else {
@@ -722,7 +722,7 @@ impl Environment {
         let optimization = self.optimization;
 
         let compiler = Rc::new(
-            move |func_template: Rc<Node<crate::ast::compiler::bound_nodes::AnalyzedPhase>>,
+            move |func_template: Rc<Node<crate::ast::nodes::AnalyzedPhase>>,
                   arg_types: &[StaticType]|
                   -> Result<(Value, StaticType), String> {
                 let mut diag = Diagnostics::new();