docs: reconcile capability ownership boundaries

[yaacovcorcos]

Summary

• add remote environments, desktop-managed SSH, direct/Tailscale access, background services, and server updates as an explicit stable capability family
• distinguish released MATLAB AnalysisRun from draft PR #129 ComputeSession in the cross-product map
• split local provider-transcript usage and API-equivalent cost review from privacy-preserving product analytics
• remove the incorrect Help link that treated the Usage page as product telemetry controls

Stack

This draft is stacked on Scient PR #105 (codex/documentation-program-progress-20260828) and should follow that documentation-program inventory/progress branch. Its linked desktop owner corrections are in scient-desktop PR #197.

Validation

• git diff --check
• documentation inventory tool tests: 2 passed

[yaacovcorcos]

Superseded by merged #107, which carries these capability-owner reconciliations into the active map and final documentation-system record after the dependent Help and Website work merged. This PR remains available as implementation history.