The terminal-output-scheduler e2e test asserts that a background marker
appears in the terminal buffer after switching to that tab. getTerminalContent
returns only the last 4000 chars of the serialized buffer; with the marker
prefixed before a 50000-char x-burst, the marker is always evicted and the
final assertion always fails.
Move the marker to the END of the burst so it survives tail truncation. The
burst itself remains the same length, so the chunked-drain invariants the
test exercises are unchanged.
Co-authored-by: Orca <help@stably.ai>