New examples/mdview2 — render-cache version of mdview: each logical
line is rendered into an EMM (char,attr) buffer once during file load
(interleaved with index_lines()), then scrolling draws straight from
the cache via ESTEX WINREST, with no re-parsing or fb() access in the
steady state. Horizontal scroll still uses the old live-render path
(Phase 5, not yet migrated).
Format and budget were derisked empirically first (tests/winrest):
confirmed ESTEX WINCOPY/WINREST buffer layout and measured EMM free
space, both folded into the implementation.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
