feat: Add CloudTrail event lookup and resource timeline

[YoungJinJung]

Summary

Add CloudTrail event lookup and resource change timeline views to unic.

Why

When something breaks, one of the first questions is: who changed what, and when? unic needs a fast way to inspect recent API activity without leaving the terminal.

Desired behavior

• Add a CloudTrail Timeline or similar feature
• Look up recent CloudTrail events by resource name/ID/ARN when possible
• Show actor, event name, timestamp, source service, and region
• Support common incident questions:
  • recent resource changes
  • IAM / Route53 / RDS / ECS / EC2 mutations
  • delete / update / modify events
• Allow drill-down into full event detail

Initial scope

• CloudTrail LookupEvents
• List + detail screen
• Resource-centric filtering where CloudTrail attributes allow it
• Recent events time window presets

Acceptance Criteria

• Operators can inspect recent CloudTrail events in unic
• Event list includes actor, API call, time, and region/account context
• Detail view shows enough request/response metadata to help with triage
• Tests cover repository parsing and TUI navigation
• README and docs are updated