Fix #64: Omit empty steps and errors from wide event logs

[mishankov]

Summary

Closes #64

Modifies the wide event logging to omit steps and errors fields when they are empty arrays, reducing log noise and improving readability.

Before

{"level":"DEBUG","name":"http.request","timestamp":"2026-03-01T19:38:32.602385+03:00","duration":195040541,"steps":[],"errors":[],"request.remoteAddr":"127.0.0.1:60449","tokens.type":"bearer","request.method":"GET","request.status":301,"serviceName":"http server"}

After

{"level":"DEBUG","name":"http.request","timestamp":"2026-03-01T19:38:32.602385+03:00","duration":195040541,"request.remoteAddr":"127.0.0.1:60449","tokens.type":"bearer","request.method":"GET","request.status":301,"serviceName":"http server"}

Changes

• Modified log/event.go: toAttrs() method now conditionally appends steps and errors attributes only when they contain data

Testing & Validation

• All existing tests pass (task test)
• Linter passes with 0 issues (task lint)
• No race conditions detected

Code Review Summary

Blockers: None (P0/P1)
Findings: No material issues identified
Risk: Minor - downstream log parsers may need to handle missing fields instead of empty arrays

Breaking Changes

Log entries will no longer contain steps: [] or errors: [] when empty. Systems parsing these logs should be updated to handle missing keys.