feat: Enhance #use directive for directories and cwd

The `#use` directive now supports referencing entire directories,
automatically including all `.myc` files within them. Additionally,
environments are now initialized with the current working directory as a
default search path, simplifying module resolution.

src/utils/tester.rs

@@ -27,8 +27,7 @@ pub fn run_functional_tests_with_optimization(enabled: bool) -> Vec<TestResult>
     let output_re = Regex::new(r";; Output: (.*)").unwrap();
 
     for entry in entries.filter_map(|e| e.ok()) {
-        let mut env = Environment::new(); // Fresh environment per test file
-        env.add_search_path(".");
+        let mut env = Environment::new().with_cwd(); // Fresh environment per test file
         env.optimization = enabled;
         let path = entry.path();
         if path.extension().is_some_and(|ext| ext == "myc") {
@@ -121,8 +120,7 @@ pub fn run_benchmarks(update: bool, filter: Option<&str>) -> Vec<BenchmarkResult
             .unwrap_or(1);
 
         // Compile once for this file (symbols/types are compatible with all fresh environments)
-        let initial_env = Environment::new();
-        initial_env.add_search_path(".");
+        let initial_env = Environment::new().with_cwd();
         
         if let Err(e) = initial_env.preload_dependencies(&content, Some(&path)) {
             results.push(BenchmarkResult {
@@ -152,8 +150,7 @@ pub fn run_benchmarks(update: bool, filter: Option<&str>) -> Vec<BenchmarkResult
         // Helper to measure sum of VM execution times over N executions in one environment
         let measure_sum =
             |n: u32, node: &crate::ast::compiler::TypedNode| -> Result<Duration, String> {
-                let env = Environment::new();
-                env.add_search_path(".");
+                let env = Environment::new().with_cwd();
                 if let Err(e) = env.preload_dependencies(&content, Some(&path)) {
                     return Err(format!("Dependency Error in measurement: {}", e));
                 }