Adds the v0.3 feature spec (source of truth for this release) and
the inline-execution implementation plan that was followed to land
the v0.3 work in the preceding commits.
Scope of v0.3:
- User seed directories (general + project)
- Improved built-in CLAUDE.md defaults (task + project)
- --project mode (type metadata, project root, git init)
- --projects filter for ctask list
- CTASK_TYPE env export
- Status-line and doctor updates
The 2026-04-06-install-workflow plan (also untracked) is left
alone -- it predates this session and is not part of v0.3.
typebasedio