Summary

Adds a slice-based Issue template so future work items are captured with a consistent structure (lane, area, priority, estimate, target sprint, acceptance criteria).

Test plan

• Confirm the template renders at Issues > New issue after merge
• Confirm YAML parses without validation errors

Summary by CodeRabbit

• New Features
  • Added a new “Slice” issue template to help users create structured slice-tracking issues.
  • Included guided fields for slice details, priority, estimate, sprint target, ownership, acceptance criteria, dependencies, and related findings.
  • Added a short guidance section linking to the canonical slice source and editing instructions.