Refactor: Replace optimization level with boolean flag

The optimizer now uses a simple boolean flag (`optimization`) instead of
an `optimization_level` (u32). This simplifies the optimizer's logic and
makes it easier to enable or disable optimizations.

The command-line interface and internal testing have been updated to
reflect this change.

src/utils/tester.rs

@@ -18,17 +18,17 @@ pub struct BenchmarkResult {
 }
 
 pub fn run_functional_tests() -> Vec<TestResult> {
-    run_functional_tests_with_level(0)
+    run_functional_tests_with_optimization(false)
 }
 
-pub fn run_functional_tests_with_level(level: u32) -> Vec<TestResult> {
+pub fn run_functional_tests_with_optimization(enabled: bool) -> Vec<TestResult> {
     let mut results = Vec::new();
     let entries = fs::read_dir("examples").unwrap();
     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.optimization_level = level;
+        env.optimization = enabled;
         let path = entry.path();
         if path.extension().is_some_and(|ext| ext == "myc") {
             let content = fs::read_to_string(&path).unwrap();
@@ -53,8 +53,8 @@ pub fn run_functional_tests_with_level(level: u32) -> Vec<TestResult> {
                                 name,
                                 success: false,
                                 message: format!(
-                                    "Level {}: Expected {}, got {}",
-                                    level, expected, val_str
+                                    "Opt {}: Expected {}, got {}",
+                                    if enabled { "ON" } else { "OFF" }, expected, val_str
                                 ),
                             });
                         }
@@ -62,7 +62,7 @@ pub fn run_functional_tests_with_level(level: u32) -> Vec<TestResult> {
                     Err(e) => results.push(TestResult {
                         name,
                         success: false,
-                        message: format!("Level {}: Error: {}", level, e),
+                        message: format!("Opt {}: Error: {}", if enabled { "ON" } else { "OFF" }, e),
                     }),
                 }
             }