Migrate to golangci-lint v2 and optimize CI/CD

[odysseus0]

Summary

• Migrates golangci-lint configuration to v2 schema
• Optimizes CI by using golangci-lint-action@v8 (eliminates 93s compilation time)
• Implements tools.go pattern for version consistency between local and CI
• Fixes gosec warnings in health check handlers

Changes

Config Migration:

• .golangci.yaml: Updated to v2 schema (default: all, nested linters.settings)
• Disabled noisy linters: funcorder, noinlineerr, wsl_v5, complexity metrics
• Kept tagliatelle enabled (new projects should enforce snake_case JSON tags)

CI Optimization:

• .github/workflows/checks.yml: Use golangci-lint-action@v8 with pre-built binaries
• Extract golangci-lint version from go.mod for local/CI parity
• Remove manual make install-tools step (action handles it)

Tool Management:

• tools/tools.go: New file with blank imports (single source of truth for tool versions)
• Makefile: Simplified to use go.mod versions (removed @version suffixes)
• Removed staticcheck (bundled in golangci-lint), added gci for import formatting

Bug Fixes:

• httpserver/handler.go: Explicitly handle w.Write() errors to satisfy gosec

Test Plan

• [x] make install-tools - Tools install correctly from go.mod
• [x] make lint - 0 issues locally
• [x] make test - All tests pass
• [x] CI will verify golangci-lint-action works correctly

Learnings Applied

All changes are based on optimizations discovered while migrating protect-rpc from golangci-lint v2.1.2 to v2.5.0, where we:

1. Discovered the tools.go pattern for version consistency
2. Found golangci-lint-action eliminates 93s build time
3. Learned v2 schema enforcement and linter configurations

🤖 Generated with Claude Code