style: format all Go code with gofmt and gofumpt
Applied gofmt -w to all source files to ensure consistent formatting.
Changes include:
- Standardized import grouping (stdlib, external, internal)
- Aligned struct field definitions
- Consistent spacing in composite literals
- Simplified code where gofmt suggests improvements
All files now pass gofmt and gofumpt strict formatting checks.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>