Add self-healing setup inventory and beginner launcher

[thatcooperguy]

Summary

Adds a larger self-healing setup push for the rootless workstation flow:

• Adds rootless install receipts under NVH_HOME/receipts with health checks, repair plans, and uninstall previews.
• Adds a remote setup catalog loader with cache and bundled fallback so profiles, packs, models, and ComfyUI examples can evolve without requiring every recommendation to be hardcoded in the wizard.
• Upgrades the offline setup helper into a local assistant endpoint that can answer setup questions using storage, jobs, receipts, catalog, ComfyUI, and model state.
• Surfaces setup inventory, catalog source, repair indicators, and an Ask Setup Helper panel in the setup wizard.
• Adds doctor checks for install receipts and setup catalog status.
• Writes receipts after ComfyUI installs, AI Studio pack installs, and selected local model downloads.

Validation

• npm run lint passed
• npm run build passed
• pytest tests/test_install_receipts.py tests/test_setup_catalog.py tests/test_setup_agent.py tests/test_studio_packs.py tests/test_comfyui_integration.py -q passed using Windows temp basetemp
• git diff --cached --check passed

Notes

The local Windows worktree still has an unstaged scripts/install.sh deletion caused by the earlier local security/quarantine issue. That deletion is intentionally not part of this PR.