`LiveOutcome::frame` was carrying the rendered bytes as a fresh
`Vec<u8>` cloned out of `RenderedFrame::rgba_bytes()`. At 60 fps
on a 1080p canvas that was an extra 8 MB allocation + memcpy per
frame on top of the clone `host.last_rendered_frame()` already
paid for. `LiveOutcome` now carries the owned `RenderedFrame`
directly, and `write_outcome` writes its `rgba_bytes()` slice
straight to stdout — same single-clone cost as the host already
incurred, no second allocation.
Small Karpathy-style follow-up from the T8 review ("the host
still copies its rendered buffer to a transient Vec<u8> before
write_all; expose &[u8] straight to write_all once the profile
shows that allocation in the top five"). Profile data is still
deferred (T9 was marked vibe-benchmarking until T10 lands a real
spec), but removing the cheap clone is structurally cleaner and
makes the dispatch path one allocation lighter regardless.
cargo test --bin ely_app: 118 passed, 0 failed, 1 ignored.
cargo test -p ely_servo_host --features servo-engine --test sidecar: 9 passed.
ZacharyZhang-NY
e02c0fd502