test(tui): mouse_selection_autocopies_on_release_without_ctrl_c is red on main (post #6228 copy-path landing)

Observed (deterministic, in isolation)

cargo test -p codewhale-tui --lib --locked \
  tui::ui::tests::mouse_selection_autocopies_on_release_without_ctrl_c -- --exact

=> FAILED, finished in 0.09s
panicked at crates/tui/src/tui/ui/tests.rs:4038:
  markdown copy must not touch the legacy status sink

Attribution (file history, not a bisect)

• The assertion comes from 0dc66e6166 (the #6156 landing; its own commit message says the test "FAILS without the fix ... proving it pins the new behavior").
• The behavior path it pins (crates/tui/src/tui/mouse_ui.rs) was last changed by ba7e7fa99 (#6228 "fragment selections copy exact text, not whole cells"), which also edited this test file — followed by the clippy sweep 10443600d.
• The current fleet/engine slices do not touch mouse_ui.rs or this test (verified: working-tree diff contains zero mouse_selection changes).

So the likely shape is: #6228 changed which selection path writes the receipt, and the #6156 status-sink assertion was not updated with it. A 10-minute bisect on ba7e7fa99 by whoever owns #6228 settles it.

Impact

Red on main; one of the pre-existing reds every lane run has to filter out. Small, but it keeps costing every reviewer the same triage.

Reported by the Codewhale night program; no fix attempted (peer-owned path).