style: enabel golangci-lint wsl_5 & whitespace

[franklinkim]

Description

Enable the wsl_v5 and whitespace golangci-lint linters and apply the resulting formatting fixes across the codebase.

Type of Change

• 🐛 Bug fix
• ✨ New feature
• 💥 Breaking change
• 📝 Documentation
• ♻️ Refactoring
• ⚡ Performance
• ✅ Tests
• 🔧 Build/CI

Changes

• Enable wsl_v5 and whitespace linters in .golangci.yaml (removed from the disabled list)
• Add pprof to lint build-tags and consolidate the goreleaser build tags into -tags=safe,pprof
• Apply whitespace/cuddling fixes across client/, cmd/, content/, and pkg/ (handler, metrics, repo)

Checklist

• My code adheres to the coding and style guidelines of the project.
• I have performed a self-review of my own code.
• I have commented on my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.