* fix: final cleanups for CGA substrate migration PR
- Update UI test fixtures to packs/data paths
- Clean CLAUDE.md/GEMINI.md to minimal per AGENTS.md
- Refactor fraction geometric construction into dedicated helper in problem_frame_contracts.py
- No TODOs left in code; notes in PR description
This completes the mechanical readiness for the CGA substrate + registry consolidation work.
* docs: include PR description for review
* chore: enforce forgejo tooling in AGENTS.md
* docs: update bootstrap skill and add git-forgejo config doc per new rules
* docs: remove deprecated git-forgejo wrapper docs
* chore: ignore local .mcp.json configuration file
* fix(ui): remove unsupported assessment.bindings usage to fix TS2339/TS7006 in constructionEvidencePanelModel
