v9.1.0 — beehave 1.0.0 knowledge integration

Knowledge

• test-stubs.md: Full rewrite incorporating beehave 1.0.0 features — beehave status (6 development stages, --json, --include-unmapped), beehave list/list -v, beehave clean, collision detection, feature stem = title slug requirement
• source-stubs.md: Updated creation order to include beehave status
• gherkin.md: Updated Related link to reference beehave status

Skills

• select-feature: Replaced manual checking with beehave status --json for project-wide overview
• accept-feature, verify-traceability: Added beehave status --json pre-check
• review-gate: Added test-stubs to available knowledge

Project

• Added [dependency-groups] with flowr>=1.0.0 in dev (PEP 735)