Add a `repos` JSONB column to the workspace table for storing
associated repository URLs and descriptions. This enables the daemon
to clone repos and set up git worktrees for agent task execution.
Structure: [{"url": "https://github.com/org/repo", "description": "..."}]
- Migration 014: adds repos column with default '[]'
- UpdateWorkspace query: supports updating repos
- Workspace API: returns repos in GET, accepts in PUT
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
