Open Codex 0.131.4

Open Codex 0.131.4

• Fix Zellij pane scroll compatibility by disabling xterm alternate-scroll mode when Open Codex detects ZELLIJ, ZELLIJ_SESSION_NAME, or ZELLIJ_VERSION.
• Preserve normal terminal behavior outside Zellij, so non-Zellij sessions still get alternate-scroll handling while inside the TUI alt screen.
• Apply the same Zellij guard across Ctrl-Z suspend/resume so pane scroll remains usable after returning to Open Codex.
• Remove the redundant background-terminal footer/status text (/ps to view · /stop to close) now that background terminals are managed through the down panel.
• Restore 0.130.x Esc routing semantics for pending steers and rejected steers, so single Esc can steer/interrupt instead of being intercepted by double-Esc rewind detection.
• Add focused regression coverage for alternate-scroll enablement inside and outside Zellij.