Document and mock the redesigned downloading state for the launcher. The
reference now replaces the action button slot with a dedicated progress
primitive, covers both card and detail-modal layouts, and records the sizing,
number formatting, container-query fallback, and sample-data expectations that
implementation work should follow.
This commit keeps the design package separate from application code so the
next UI/backend changes can be reviewed against a stable reference.
Test Plan:
- git diff --cached --check
Refs: local design reference update
ddidderr
e308009a08
