Remove unused system library and simplify environment initialization

The `system.myc` file, containing macros and core utilities, has been
removed as its functionality is now handled by an embedded string. This
simplifies the build process and eliminates a file that was no longer
strictly necessary.

Additionally, the `with_cwd()` method on the `Environment` has been
removed. The environment now automatically adds the current working
directory and its `rtl` subdirectory to the search paths during
initialization. This streamlines the setup for file-based usage and
ensures standard search paths are always considered.

src/main.rs

@@ -61,7 +61,7 @@ impl Default for CompilerApp {
             })
             .unwrap_or_default();
 
-        let env = Environment::new().with_cwd();
+        let env = Environment::new();
 
         Self {
             source_code: String::from(
@@ -96,14 +96,10 @@ impl CompilerApp {
         self.trace_logs.clear();
 
         // Reset environment for a fresh run
-        self.env = Environment::new().with_cwd();
+        self.env = Environment::new();
         self.env.optimization = true;
 
         let res = (|| -> Result<(myc::ast::types::Value, std::time::Duration), String> {
-            if let Err(e) = self.env.preload_dependencies(&self.source_code, self.current_example_path.as_deref()) {
-                return Err(format!("Dependency Error: {}", e));
-            }
-
             let start_run = std::time::Instant::now();
             let result = if self.debug_enabled {
                 let (res, logs) = self.env.run_debug(&self.source_code)?;
@@ -162,14 +158,9 @@ impl CompilerApp {
     }
 
     fn dump_ast(&mut self) {
-        self.env = Environment::new().with_cwd();
+        self.env = Environment::new();
         self.env.optimization = true; // Enable optimization for AST dump
         
-        if let Err(e) = self.env.preload_dependencies(&self.source_code, self.current_example_path.as_deref()) {
-            self.output_log = format!("Dependency Error: {}", e);
-            return;
-        }
-
         match self.env.dump_ast(&self.source_code) {
             Ok(dump) => {
                 self.output_log = format!("--- BOUND AST DUMP ---\n\n{}", dump);