[hammondr]

Problem

When an agent updates its state in a background pane (needs-input or done), the pane-background indicator unzooms the user's current window and moves focus to the triggering pane. Anyone who has zoomed one pane to concentrate on it loses that zoom whenever any other tracked pane changes state, and focus jumps away from where they were working.

Root cause

apply_pane_style and reset_pane_style in scripts/agent-state.sh set the pane background with tmux select-pane -t <pane> -P "bg=...". On tmux 3.x, select-pane -P targeting a non-active pane changes the active pane and clears the window zoomed flag as a side effect, even when the only intent is to set a style. The functions then call select-pane -t <previous-active> to put focus back, which restores the active pane but cannot restore the zoom.

Reproduction on tmux 3.7b, starting from a zoomed 2-pane window:

zoom pane %42 (active)               -> window_zoomed_flag=1  active=%42
select-pane -t %43 -P "bg=colour52"  -> window_zoomed_flag=0  active=%43

The same side effect fires for every state that tints a background pane, so a long-running agent that finishes in a hidden pane yanks the user out of their zoom.

Fix

Set the pane background through the pane-level window-style option instead of select-pane -P:

tmux set-option -p -t <pane> window-style "bg=<color>"   # apply
tmux set-option -pu -t <pane> window-style               # clear

set-option -p writes only the pane option. It leaves the active pane and the zoom flag untouched, so no focus juggling or restore call is needed.

This PR converts every set and clear site to window-style so a tint applied one way is cleared the same way:

• scripts/agent-state.sh: apply_pane_style and reset_pane_style
• scripts/pane-focus-in.sh: the two focus-in clear paths
• scripts/reset_all.sh: the bulk reset loop

Verification

Primitive, on tmux 3.7b, starting from a zoomed window:

zoom pane %47 (active)
set-option -p -t %48 window-style "bg=colour52"
-> window_zoomed_flag=1  active=%47  pane %48 background=colour52
set-option -pu -t %48 window-style
-> window-style cleared

End to end: a background pane transitioning to done while another pane is zoomed keeps the zoom and the active pane, tints the background pane, and clears the tint when that pane is focused.

Compatibility and scope

window-style is a standard pane option in tmux 3.x, and both select-pane -P and set-option -p window-style set the pane background, so the rendered result is unchanged. The Knight Rider animation writes a status-bar frame index and does not color panes, so it is unaffected. The active-pane border, window-title styling, and status indicators use set-window-option and status formats rather than select-pane, so they are unaffected as well.

[hammondr]

Closing as a duplicate of #6, which predates this by six weeks and makes the same change: pane background set through set-option -p window-style in place of select-pane -P, across agent-state.sh, pane-focus-in.sh, and reset_all.sh. I opened this without checking existing PRs first. Deferring to #6, where I have left an independent confirmation on tmux 3.7b.