PROJECT-CONTORL/openspec/changes/update-api-consistency/specs/task-management/spec.md

MODIFIED Requirements

Requirement: Optimistic Locking for Task Updates

The system SHALL use optimistic locking to prevent concurrent update conflicts on tasks.

Scenario: Concurrent update detected

• WHEN user A and user B both load task at version 1
• WHEN user A saves changes, incrementing version to 2
• WHEN user B attempts to save with version 1
• THEN system returns 409 Conflict error
• AND response includes a human-readable message instructing refresh and retry
• AND response includes the current and provided version numbers

Scenario: Sequential updates succeed

• WHEN user loads task at version N
• WHEN user saves changes with correct version N
• THEN system accepts update and increments version to N+1