fix(ghostel): support ghostel >= 0.22.0 (ghostel--copy-mode-active removed)

[dsdshcym]

Problem

After upgrading ghostel past commit bdd2b85 (v0.22.0, "Add eat-style input modes"), claude-code buffers are stuck at 80 columns wide.

Root cause

ghostel bdd2b85 removed ghostel--copy-mode-active and replaced it with ghostel--input-mode. The three ghostel backend methods still referenced the old variable.

When claude-code--adjust-window-size-advice fires during window resize, it calls claude-code--term-in-read-only-p → ghostel--copy-mode-active → void-variable error. This error is silently swallowed by Emacs's C-level window resize callback, causing the advice to return nil and suppress SIGWINCH.

Without SIGWINCH, Claude Code's PTY is never notified of the correct terminal width and stays at the 80-column fallback set at spawn time. (The buffer is not yet displayed in any window when ghostel-exec is called, so it falls back to 80×24.)

Note: ghostel's libghostty internal model does resize correctly — only Claude Code's PTY signal is suppressed, so output wraps at 80 columns even in a wider window.

What changed in ghostel

Old (< 0.22.0)	New (>= 0.22.0)
ghostel--copy-mode-active (bool)	ghostel--input-mode (symbol: semi-char/char/emacs/copy/line)
ghostel-copy-mode-exit	ghostel-readonly-exit

Fix

• Extract claude-code--ghostel-in-copy-mode-p helper that detects the API version at runtime
• New API: (memq ghostel--input-mode '(copy emacs)) (>= 0.22.0)
• Old API fallback: (bound-and-true-p ghostel--copy-mode-active) (< 0.22.0)
• ghostel-copy-mode-exit → ghostel-readonly-exit with fboundp guard for backward compat

Test plan

• Launch claude-code with ghostel >= 0.22.0 — buffer should use full window width (not 80 cols)
• Copy mode (ghostel-copy-mode) still works (read-only detection correct)
• Exiting copy mode works and restores keymap
• Verify still works with old ghostel (< 0.22.0) via bound-and-true-p / fboundp guards

🤖 Generated with Claude Code

[dustinfarris]

@stevemolitor does this look ok to you? should it be a breaking change like #136?