Why: the tui_gateway live formatter (`_format_live_context_output`, used when
the session runs on a compute host) renders its own summary and never got the
"Context files" block, and `session.context_breakdown` had no structured rows,
so Desktop's popover could not show them. The formatter now appends
render_context_file_lines() with the session cwd bound (the RPC thread has no
session context, so the discovery walk would key on the backend's cwd), and
the RPC payload gains a `context_files` list (contract + generated TS/OpenRPC
+ Desktop type). The docs sentence is scoped to the surfaces that render it.
A file whose content _scan_context_content replaces with a BLOCKED marker was
reported "loaded"; the manifest now runs the same scan and reports `blocked`.
The module docstring names the frontmatter-strip / chain-cap approximations
and drops the product-name attribution (credit stays in the PR body).
e860b8e4e4