- Add #[allow(dead_code)] attributes to unused functions and variants
- Fix unused variable warning by prefixing with underscore
- Make TestSuites fields optional with default values
- Fix Option<e> typo to Option<Error> in model.rs
- Add test for parsing integrationv2_sni_match.xml
- Mark tests with missing files as ignored

- Add test_parse_integration_files.rs to verify parsing of all integration XML files
- Add test_snapshot_integration.rs to test snapshot creation and storage
- Add test_cli_integration.rs to test CLI functionality
- Update main.rs to support --dir parameter in capture and list commands

This ensures the junit-snapshot tool can successfully parse and use all the
integration test XML files.

- Add all integration test XML files as test inputs
- Move snapshot_testing_utility_design_doc.md from docs/ to tools/
- These XML files are used by the new test suite to verify parsing
  and snapshot functionality

Add a comprehensive guide for new developers on how to use the
junit-snapshot tool, including:
- Initial setup and building
- Creating and managing snapshots
- Comparing test results against snapshots
- Updating snapshots as tests evolve
- Best practices and workflow examples

This guide will help onboard new developers and provide a reference
for working with the snapshot testing utility.

Replace symlink and PATH instructions with cargo install instructions,
which is the recommended way to install Rust binaries. This provides
a cleaner installation process that leverages Cargo's built-in
package management capabilities.

- Add integrationv2_happy_path.xml (1.2MB) as a test input file
- Modify parser to use buffered reading for large XML files
- This change enables the previously ignored tests that depend on this file
- The buffered approach is more memory efficient for large files

- Remove ignore annotations from tests that use integrationv2_happy_path.xml
- Now that the large test file is available and the parser is improved,
  these tests can run successfully
- This completes the test coverage for the snapshot functionality

This commit addresses two issues in the junit-snapshot tool:
1. Fix type error in model.rs where 'error: Option<e>' was incorrectly defined
2. Improve XML parsing to handle large files by:
   - Using BufReader with streaming parser instead of loading entire file
   - Calculating total test counts from individual test suites when not set in root
   - Properly handling memory-efficient deserialization

These changes allow the parser to successfully process large XML files like
integrationv2_happy_path.xml without memory issues while maintaining
accurate test statistics.

Remove unused Read import and add #[allow(dead_code)] attribute to
parse_junit_xml function to eliminate compiler warnings.

This commit adds a new 'compare' command to the JUnit snapshot utility that:
- Compares a new JUnit file against a baseline snapshot
- Detects matching, different, new, and missing tests
- Shows detailed information about test status changes
- Uses colored output to highlight differences
- Supports a diff-only flag to show only differences
- Supports a fail-on-diff flag for CI integration

Also adds comprehensive tests for the compare command and updates documentation.

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