Add CI workflows, linting configuration, and code quality improvements

[corylanou]

Summary

This PR adds comprehensive CI/CD infrastructure, linting configuration, and various code quality improvements to the LTX project.

Changes Made

CI/CD Infrastructure

• Added GitHub Actions workflows:
  • test-and-lint.yml: Runs tests across Go 1.22, 1.23, 1.24, executes linters (go fmt, go vet, staticcheck, revive), and builds the project
  • race-detection.yml: Prepared for future race condition testing (currently disabled)
• Added .revive.toml: Comprehensive linting configuration with appropriate rules for the project

Code Quality Improvements

• Fixed all linter warnings across the codebase:
  • Added missing package documentation comments
  • Fixed receiver naming consistency
  • Removed unused parameters and return values
  • Improved error handling patterns
  • Fixed variable naming (e.g., SQLITE_DATABASE_HEADER_STRING → sqliteDatabaseHeaderString)
  • Added missing JSON marshaling documentation
  • Fixed type assertion safety checks

Documentation Updates

• Enhanced README.md:
  • Improved formatting with proper markdown headers
  • Added detailed checksum design documentation explaining database vs file checksums
  • Clarified security considerations for page index inclusion in file checksums
  • Fixed header layout table to show accurate field offsets and sizes

Testing Enhancements

• Added comprehensive test: TestPageIndexInChecksum to verify page index is properly included in file checksum calculation

Build Configuration

• Updated .gitignore: Added Go binary exclusions (cmd/ltx/ltx, ltx)

File Changes Summary

• CI/CD: Added 2 new GitHub Actions workflows (123 lines)
• Linting: Added .revive.toml configuration (56 lines)
• Code fixes: Updated 15 Go files to address linter warnings
• Tests: Added new test case for page index checksum validation (113 lines)
• Documentation: Enhanced README with checksum design section

Test Plan

• All tests pass across Go 1.22, 1.23, 1.24
• No linting issues (go fmt, go vet, staticcheck, revive)
• Builds successfully
• New test validates page index security

Note

The snapshot validation feature that was initially included in this PR has been moved to a separate branch (snapshot-validation) for its own PR, keeping this PR focused on CI/CD, linting, and code quality improvements.

🤖 Generated with Claude Code