v2.12.0

Features

• Subtask parallelism: Squad agents can now have subtasks that fan out as separate Fleet tasks within the same phase
• All subtasks run concurrently and results are merged back into a single agent result
• AI repo analysis can optionally return subtasks for naturally parallelizable work
• Subtasks persist through .copex/squad.json save/load

Tests

• 9 new tests for subtask parallelism
• 588 total tests passing