Follow light/dark appearance in the tmux status bar

The status bar was five hardcoded tangere-dark colours, so in light mode the
pale #fdfdd9 text landed on a white background and became unreadable. That was
the real reason Auto appearance "never worked with the terminal setup" — ghostty
was switching correctly all along.

Split the colours into tmux-light.conf and tmux-dark.conf. The dark file is
extracted byte-exact from the previous config; the light file is the same layout
with each colour swapped for the tangere-light palette entry at the same index,
so roles are preserved (text on an accent uses the theme background, which
inverts from #1a2938 to #fdfdfa).

tmux 3.6+ learns the terminal's theme over OSC 2031, so this keys off the
appearance change itself rather than a schedule, and behaves identically whether
that came from Auto at sunrise/sunset or a manual toggle. Three hooks: the two
theme hooks react to a change, and client-attached covers a client attaching
mid-way, since those two only fire on a change. Sourcing is idempotent so the
overlap is harmless.

This replaces the dark-mode-notify launchd agent removed in 59d5622, which could
not have worked: it re-sourced .zshrc inside each shell, but the status bar
belongs to the tmux server.

Verified by round trip: flipping to Light switched #{client_theme} and applied
the light palette, and returning to Dark restored it. A running nvim does not
follow a live change (docs: the TUI sets 'background' on startup); noted in the
README.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -68,12 +68,24 @@ Most of this is now handled natively and needs no configuration:
 - **bat** picks a theme per invocation from `BAT_THEME_LIGHT` / `BAT_THEME_DARK`.
 - **delta** and **nvim** detect the terminal background themselves.
 
-Still outstanding: the tmux status bar is hardcoded to dark-tuned colours, so it
-is unreadable in light mode. tmux has `client-light-theme` and
-`client-dark-theme` hooks for exactly this — not yet wired up.
+The tmux status bar needs help, because its colours are set explicitly. They live
+in `tmux-light.conf` and `tmux-dark.conf` — the same layout, with each colour
+taken from the matching tangere palette index — and `tmux` sources one of them
+from three hooks:
 
-Both machines currently run pinned Dark, so the delta and nvim behaviour above is
-documented-but-untested here. Worth re-checking when Auto goes back on.
+- `client-light-theme` / `client-dark-theme` react to a change,
+- `client-attached` picks the right one for a client that attaches mid-way, since
+  the two above only fire on a change.
+
+Because this keys off the terminal's reported theme rather than a schedule, it
+behaves identically whether the change came from Auto at sunrise/sunset or from
+toggling Light/Dark by hand — nothing in the chain knows why it changed.
+
+> [!NOTE]
+> A running nvim will not follow a live change: the docs are explicit that the
+> TUI sets `background` *on startup* if it can detect it. New instances are
+> fine; existing ones need `:set background=light` or a restart. delta is
+> per-invocation so should be fine, but that is untested here.
 
 > [!NOTE]
 > This previously used [`dark-mode-notify`](https://github.com/bouk/dark-mode-notify)

bootstrap.sh

@@ -8,6 +8,8 @@ echo "Sym-linking the various config files"
 test -L $HOME/.gitignore || ln -f -s $BASEDIR/gitignore $HOME/.gitignore
 test -L $HOME/.hushlogin || ln -f -s $BASEDIR/hushlogin $HOME/.hushlogin
 test -L $HOME/.tmux.conf || ln -f -s $BASEDIR/tmux $HOME/.tmux.conf
+test -L $HOME/.tmux-light.conf || ln -f -s $BASEDIR/tmux-light.conf $HOME/.tmux-light.conf
+test -L $HOME/.tmux-dark.conf || ln -f -s $BASEDIR/tmux-dark.conf $HOME/.tmux-dark.conf
 test -d $HOME/.config/sheldon || mkdir $HOME/.config/sheldon
 test -L $HOME/.config/sheldon/plugins.toml || ln -f -s $BASEDIR/sheldon.toml $HOME/.config/sheldon/plugins.toml
 test -L $HOME/.zsh || ln -f -s $BASEDIR/zsh $HOME/.zsh

tmux

@@ -33,9 +33,6 @@ set -g default-terminal "$TERM"
 # Allow OSC 8 links
 set -ga terminal-features "*:hyperlinks"
 
-# Tweak status bar styles
-set -g status-style bg=default,fg='#fdfdd9'
-
 # Set status bar length
 set -g status-left-length 40
 set -g status-right-length 60
@@ -43,14 +40,16 @@ set -g status-right-length 60
 # Center the window list
 set -g status-justify centre
 
-# Left side: session name with blue accent
-set -g status-left "#[fg=#1a2938,bg=#8fb4cd,bold]  #S #[fg=#8fb4cd,bg=default]\ue0b0"
+# Status bar colours live in ~/.tmux-light.conf and ~/.tmux-dark.conf. tmux
+# learns the terminal's theme over OSC 2031, so this reacts to the appearance
+# change itself, whether that came from Auto at sunrise/sunset or a manual
+# toggle, since nothing here knows why it changed.
+set-hook -g client-light-theme 'source-file ~/.tmux-light.conf'
+set-hook -g client-dark-theme 'source-file ~/.tmux-dark.conf'
 
-# Right side: multi-segment with transitions
-set -g status-right "#[fg=#6dafb5,bg=default]\ue0b2#[fg=#1a2938,bg=#6dafb5] %H:%M #[fg=#bb98d9,bg=#6dafb5]\ue0b2#[fg=#1a2938,bg=#bb98d9] %d-%b "
+# Those hooks only fire on a change, so also pick the right palette whenever a
+# client attaches. Sourcing is idempotent, so the overlap is harmless.
+set-hook -g client-attached 'if -F "#{==:#{client_theme},light}" "source-file ~/.tmux-light.conf" "source-file ~/.tmux-dark.conf"'
 
-# Inactive windows (no powerline symbols)
-setw -g window-status-format "#[fg=#2f4656,bg=default] #I #W "
-
-# Active window (cyan highlight, no powerline)
-setw -g window-status-current-format "#[fg=#1a2938,bg=#6dafb5,bold] #I #W "
+# Default before any client has attached and reported a theme.
+source-file ~/.tmux-dark.conf

tmux-dark.conf

@@ -0,0 +1,21 @@
+# tangere-dark status bar, sourced by the client-dark-theme hook in ~/.tmux.conf
+#
+# Colours are tangere-dark palette entries so the bar matches the ghostty theme.
+# Text sitting on an accent uses the theme background (#1a2938).
+#   #fdfdd9 foreground   #1a2938 background   #2f4656 dim (15)
+#   #8fb4cd blue (4)     #6dafb5 cyan (2)     #bb98d9 magenta (5)
+
+# Tweak status bar styles
+set -g status-style bg=default,fg='#fdfdd9'
+
+# Left side: session name with blue accent
+set -g status-left "#[fg=#1a2938,bg=#8fb4cd,bold]  #S #[fg=#8fb4cd,bg=default]\ue0b0"
+
+# Right side: multi-segment with transitions
+set -g status-right "#[fg=#6dafb5,bg=default]\ue0b2#[fg=#1a2938,bg=#6dafb5] %H:%M #[fg=#bb98d9,bg=#6dafb5]\ue0b2#[fg=#1a2938,bg=#bb98d9] %d-%b "
+
+# Inactive windows (no powerline symbols)
+setw -g window-status-format "#[fg=#2f4656,bg=default] #I #W "
+
+# Active window (cyan highlight, no powerline)
+setw -g window-status-current-format "#[fg=#1a2938,bg=#6dafb5,bold] #I #W "

tmux-light.conf

@@ -0,0 +1,22 @@
+# tangere-light status bar, sourced by the client-light-theme hook in ~/.tmux.conf
+#
+# Same layout as tmux-dark.conf, with each colour swapped for the tangere-light
+# palette entry at the same index. Roles are preserved: text on an accent uses
+# the theme background, which is now light rather than dark.
+#   #000000 foreground   #fdfdfa background   #d1d1d1 dim (15)
+#   #223355 blue (4)     #004c73 cyan (2)     #663d52 magenta (5)
+
+# Tweak status bar styles
+set -g status-style bg=default,fg='#000000'
+
+# Left side: session name with blue accent
+set -g status-left "#[fg=#fdfdfa,bg=#223355,bold]  #S #[fg=#223355,bg=default]\ue0b0"
+
+# Right side: multi-segment with transitions
+set -g status-right "#[fg=#004c73,bg=default]\ue0b2#[fg=#fdfdfa,bg=#004c73] %H:%M #[fg=#663d52,bg=#004c73]\ue0b2#[fg=#fdfdfa,bg=#663d52] %d-%b "
+
+# Inactive windows (no powerline symbols)
+setw -g window-status-format "#[fg=#d1d1d1,bg=default] #I #W "
+
+# Active window (cyan highlight, no powerline)
+setw -g window-status-current-format "#[fg=#fdfdfa,bg=#004c73,bold] #I #W "