fix: treemapperignore now properly takes precedence over gitignore

- Fixed pattern order: .gitignore first, then .treemapperignore
- Added 50 comprehensive tests covering all documented features
- Tests for all default ignore patterns (JS, Java, Go, .NET, IDE, OS)
- Tests for CLI features, Python API edge cases, content placeholders
- Tests for hierarchical ignore files and precedence rules

Author: nikolay-e

src/treemapper/ignore.py

@@ -132,8 +132,8 @@ def get_ignore_specs(
 
     if not no_default_ignores:
         patterns.extend(DEFAULT_IGNORE_PATTERNS)
-        patterns.extend(_aggregate_ignore_patterns(root_dir, ".treemapperignore"))
         patterns.extend(_aggregate_ignore_patterns(root_dir, ".gitignore"))
+        patterns.extend(_aggregate_ignore_patterns(root_dir, ".treemapperignore"))
 
     if custom_ignore_file:
         patterns.extend(read_ignore_file(custom_ignore_file))