fix(vterm): use a block cursor in vterm-copy-mode

The 3-pixel bar was visible but a block matches the rest of my Emacs cursor and lets the standard cursor color and `blink-cursor-mode' behavior carry through unchanged. Same enter/exit semantics: forced visible on entry, buffer-local override killed on exit so the live terminal goes back to the TUI's chosen state.

Update the test expectations and rename the "prior-was-box" boundary test to "prior-was-hbar" so it still proves the override does something (the prior and the override would otherwise both be `box').

0 files changed, 0 insertions, 0 deletions