navigate_pane_up config has no effect and does not displace the default k

[inouetakuya]

Is this a reproducible bug?

• I confirm this is a reproducible bug, not a feature request, idea, question, contribution proposal, or direction check.
• I reproduced this bug on the version and environment reported below using the exact steps provided.

Current behavior

navigate_pane_up has no effect. The configured key never fires, and the built-in k keeps working, so the default is not displaced. herdr config check still reports config: ok.

In the same navigate mode, navigate_workspace_up = ["up", "ctrl+p"] works as configured: ctrl+p moves the workspace selection and the arrow key still works.

Also observed: ctrl+k moves the selection up even when navigate_pane_up is unset.

Expected behavior

navigate_pane_up binds the configured key and displaces the default k, the same way navigate_workspace_up does.

Reproduction

1. Add to ~/.config/herdr/config.toml:

[keys]
navigate_pane_up = "ctrl+x"

2. Run herdr config check. It prints config: ok.
3. Run herdr server reload-config.
4. Open navigate mode and select a pane row.
5. Press ctrl+x. The selection does not move.
6. Press x. The selection does not move.
7. Press k. The selection moves up.

Impact

Navigate-mode pane movement cannot be remapped. j and k are effectively fixed, so a ctrl-based layout is possible for workspace rows but not for pane rows.

Environment

• Herdr version: 0.7.5
• Update channel (stable or preview): stable
• Operating system: macOS 26.5.2
• Terminal: Ghostty 1.3.1
• Shell, if relevant: zsh
• Relevant config, if any: goto = "prefix+l", navigate_workspace_up = ["up", "ctrl+p"], navigate_workspace_down = ["down", "ctrl+n"]