feat: theme Firefox from the accent via pywalfox

udt-accent now rewrites ~/.cache/wal/colors.json as a fixed Catppuccin
Macchiato palette with the wallpaper's accent in the cursor and the two
highlight slots, then runs `pywalfox update`.

colors.json is the only file pywalfox reads, so this is the only way Firefox
can follow the accent. Overwriting it wholesale costs nothing: wallp already
rewrote it moments earlier via `wal --theme`, and nothing else consumes it.
kitty reads its own current-theme.conf, so the terminal palette is unaffected.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015gbjA2bmswN8jyPDKzrvqe

1 files changed, 20 insertions, 9 deletions

diff --git a/AGENTS.md b/AGENTS.md
index cbb4c14..bd67064 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -19,20 +19,30 @@ One colour moves: `@accent`. `bin/udt-accent` reads the current wallpaper,
 extracts its signature colour, and snaps it to the nearest of ten Catppuccin
 accents by perceptual hue in CIELAB. `wallp` calls it on every wallpaper change.
 
-It writes three things: `~/.cache/wal/udt-accent.rasi` (rofi),
-`~/.cache/wal/udt-border.lua` (Hyprland), and the accent substitution in
-`~/.cache/wal/dunstrc`.
+It writes four things: `~/.cache/wal/udt-accent.rasi` (rofi),
+`~/.cache/wal/udt-border.lua` (Hyprland), the accent substitution in
+`~/.cache/wal/dunstrc`, and `~/.cache/wal/colors.json` (Firefox, via
+pywalfox).
 
 **Extraction is deliberately isolated from the pywal cache.** It calls
 `pywal.backends.colorz.get()` directly, which returns a list and writes nothing.
 Running `wal -i` instead would rewrite all of `~/.cache/wal`, including the
 terminal's ANSI colours, and that is the exact failure this design exists to
-avoid. If you change that function, verify `~/.cache/wal/colors.json` is
-byte-identical afterwards.
-
-Not everything tracks the wallpaper. rofi, dunst and Hyprland borders do; conky,
-Qt, GTK and waybar sit on fixed lavender, which is also the fallback when a
-wallpaper is too grey to snap. Qt and GTK apps only reread a theme on restart,
+avoid. If you change `signature_color()`, verify it still writes nothing.
+
+`colors.json` is the one pywal file `udt-accent` does rewrite, and it rewrites
+it wholesale rather than editing it: a fixed Macchiato palette with the accent
+in the cursor and the two highlight slots. That is deliberate. pywalfox reads
+`colors.json` and nothing else, so it is the only way Firefox can follow the
+accent, and overwriting it costs nothing because nothing else reads it. In
+particular kitty reads `~/.config/kitty/current-theme.conf`, not this file, so
+the terminal palette stays fixed no matter what the wallpaper looks like. The
+write lands after `wallp` has already run `wal --theme`, so it wins; reorder
+those two and pywal's wallpaper-derived colours come back.
+
+Not everything tracks the wallpaper. rofi, dunst, Hyprland borders and Firefox
+do; conky, Qt, GTK and waybar sit on fixed lavender, which is also the fallback
+when a wallpaper is too grey to snap. Qt and GTK apps only reread a theme on restart,
 so a moving accent there would leave running apps disagreeing with new ones.
 
 ## Verifying visual changes
@@ -104,6 +114,7 @@ them by exit code: rofi exits non-zero for ordinary reasons such as Escape.
 | --- | --- |
 | rofi | nothing; the theme is read per launch |
 | dunst | `udt-accent` restarts it |
+| Firefox | `udt-accent` runs `pywalfox update` |
 | Hyprland | `hyprctl reload` |
 | waybar | `killall -SIGUSR2 waybar` |
 | kitty | `pkill -USR1 -x kitty` |