Seven near-identical #[test] fns become one table test over the same inputs
(SGR banners, cursor/erase/private modes, OSC with BEL and ST, \r redraws,
sequences cut by the pipe, plain multi-byte text) plus the existing
sanitized_for_ui_only_touches_log_lines. Same coverage, two tests: the
salvage bar is ≤2 invariant tests per fix.
Verified with the function and tests extracted into a standalone
`rustc --test` binary (cargo test on this host fails in libdbus-sys, a
missing system header unrelated to this crate's code).
22b576999f