Fix build issues and clean up temporary files (#188)

- Fix Block::fill method compilation issue by moving conditional compilation inside method body
- Remove accidentally committed temporary files (.DS_Store, .cache/, test.eu)
- Update .gitignore to prevent future commits of temporary files
- Ensures clean builds in both debug and release modes

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

Author: gmorpheme

.DS_Store

@@ -4,3 +4,8 @@
 /harness/test/.result/
 /src/syntax/grammar.rs
 /src/syntax/string_pattern.rs
+
+# Temporary files
+.DS_Store
+.cache/
+test.eu

.cache/41/cache.db

@@ -60,8 +60,8 @@ impl Block {
     }
 
     /// Fill areas that are meant to be dead with 0xff to aid debugging
-    #[cfg(debug_assertions)]
     pub fn fill(&self, offset_bytes: usize, size_bytes: usize) {
+        #[cfg(debug_assertions)]
         unsafe {
             let start = self.ptr.as_ptr().add(offset_bytes);
             let mem = std::slice::from_raw_parts_mut(start, size_bytes);