feat(palette): generate the Kvantum theme so Qt apps follow the scheme

Qt and GTK were the one part of the desktop the palette never reached: Kvantum
was pinned to a hand-installed catppuccin-macchiato-lavender directory, so
pcmanfm-qt and every other Qt app stayed Macchiato no matter which scheme was
selected.

A Kvantum theme is a .kvconfig of colours and a .svg of widget artwork with
colours baked into the paths, which looked like it needed redrawing. It did
not: the SVG carries only 27 distinct colours, 12 of them palette colours and
the rest neutral greys that are shading, not theme colour. Both files are now
templates with the 12 as placeholders, derived from the theme this desktop was
already running.

Installs to ~/.config/Kvantum/udt/ under one fixed name for every scheme, so a
switch needs no change to kvantum.kvconfig and leaves no stale theme behind.
Adds accent_dim and accent_bright roles for Kvantum's hover and pressed states.

Verified: no placeholders survive generation, the SVG still parses as XML, and
pcmanfm-qt picks up the new colours on restart. Qt reads a theme at startup
only, so running apps need restarting; AGENTS.md says so.

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

1 files changed, 24 insertions, 0 deletions

diff --git a/bin/udt-palette b/bin/udt-palette
index 18dc0b1..edde7f3 100755
--- a/bin/udt-palette
+++ b/bin/udt-palette
@@ -223,6 +223,28 @@ def gen_kitty(res, scheme, palette):
     return "\n".join(lines) + "\n"
 
 
+KVANTUM_ROLES = ["bg", "bg_alt", "surface", "surface_alt", "surface_high",
+                 "fg", "fg_dim", "fg_faint", "mid_high", "accent",
+                 "accent_dim", "accent_bright", "highlight", "critical"]
+
+
+def gen_kvantum(res, scheme, palette, template):
+    """Kvantum: substitute the palette into the widget theme.
+
+    A Kvantum theme is a .kvconfig of colours and a .svg of widget artwork with
+    colours baked into the paths. Only the palette colours are placeholders;
+    the neutral greys in the SVG are shading and shadow, not theme colour, so
+    they are left exactly as upstream drew them.
+
+    Derived from the catppuccin-macchiato-lavender theme, which is what this
+    desktop was already running by hand.
+    """
+    out = template
+    for role in KVANTUM_ROLES:
+        out = out.replace(f"@{role.upper()}@", hex6(res[role]))
+    return out
+
+
 def gen_homepage(res, scheme, palette):
     """gethomepage: a custom.css overriding its ten-step colour ramp.
 
@@ -414,6 +436,8 @@ TARGETS = [
     ("templates/conky.conf", gen_conky, "templates/conky.conf.in"),
     ("bin/udt_colors.py", gen_accent_py, None),
     ("templates/homepage/custom.css", gen_homepage, None),
+    ("templates/kvantum/theme.kvconfig", gen_kvantum, "templates/kvantum/theme.kvconfig.in"),
+    ("templates/kvantum/theme.svg", gen_kvantum, "templates/kvantum/theme.svg.in"),
 ]