0.4.3

This patch release adds Sprint records and strengthens board integrity,
interchange, and cross-platform CLI reliability without breaking the existing
CLI contract.

Added

• Added Sprint Goal achievement tracking and Sprint Goal reports.
• Added separate Sprint Retro and Review records with linked action PBIs and
  Sprint context.
• Preserved Sprint child records across board export/import and backend
  migrations.

Fixed

• Strengthened Sprint deletion, goal-outcome, and record-integrity checks.
• Prevented Windows CLI stack overflows during completion, shell, and
  automation processing.
• Isolated the doctor check's Windows executable from parallel integration
  tests.