el_runtime: http_response() JSON-encoded the body via jb_emit_escaped(),
which stops at the first null byte. PNG/binary files contain null bytes
at byte 8 (IHDR chunk length), so only 8 bytes were served — browsers
received a corrupt/truncated image and showed broken icons.
Fix: when _tl_fs_read_len > 0 (binary fs_read), copy raw bytes into a
thread-local side-channel (_tl_binary_body/_tl_binary_size) and write
the sentinel "__el_binary__" into the envelope body field. http_send_response()
detects the sentinel and substitutes the real bytes for sending.
checkout.el: .checkout-shell, .checkout-summary, and .checkout-form-wrap
had no CSS, leaving the page left-aligned and single-column. Added grid
layout (2-col desktop, 1-col mobile), max-width centering, and sticky
order summary.
will.anderson