LLC: no way to archive/delete companies (only projects have /archive); stale companies accumulate #12212

Summary

There is no usable way to archive or delete companies (and lifecycle actions generally aren't surfaced). Only POST /api/llc/projects/{project_id}/archive exists; there is no company archive endpoint, and no soft-delete/archive field on the company model. Test/abandoned companies accumulate with no cleanup path (compounding the "stuck in onboarding" state).

Details / evidence

• Archive endpoints present: only projects/{id}/archive. No companies/{id}/archive, no programs/portfolios archive.
• A DELETE /api/llc/companies/{id} route exists in code but is not exposed/usable from the UI, and there is no archive (soft-delete) alternative.

Impact

Operators cannot clean up or retire companies/projects; the company list fills with stale entries (all showing onboarding), with no archive or delete affordance.

Request

Add company archive (soft-delete) + expose delete/archive lifecycle actions in the UI for companies and projects; consider a consistent archive across the portfolio/program/project/company hierarchy.