theming: YAMIS app icons under Papirus-Fred

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017EHJfY5Q72punsWX38nY1w

settings/theming.nix

@@ -293,6 +293,32 @@ let
     ''misc={background_color="rgb(${s.base00})"}''
   ] + "})");
 
+  # ── App icons ──────────────────────────────────────────────────────────
+  # YAMIS draws the app icons in the launcher. Picked over the far bigger
+  # monochrome sets because coverage beats library size: it is the only one
+  # still shipping commits, so it has the apps actually installed here
+  # (zen, ghostty, vesktop, bazaar, faugus, protonplus) where the 10k-icon
+  # archives — Suru++ Asprómauros, dead since 2019 — do not.
+  #
+  # Not in nixpkgs. Upstream is a bare icon tree with the theme at its root,
+  # so the "build" is a copy into the directory name the spec resolves by.
+  #
+  # FollowsColorScheme=true is a KDE key: only Plasma rewrites the embedded
+  # <style id="current-color-scheme"> block. Anywhere else — quickshell and
+  # GTK here — the icons render at that block's literal fallback, #d8dee9,
+  # a cool light grey that reads on every wallpaper's dark bar. Tinting per
+  # wallpaper would mean a sed over all 6101 files per theme, so the app
+  # icons deliberately stay one fixed colour while the folders track.
+  yamisIcons = pkgs.runCommand "yamis-icon-theme" { } ''
+    mkdir -p $out/share/icons
+    cp -r ${pkgs.fetchgit {
+      url = "https://bitbucket.org/dirn-typo/yet-another-monochrome-icon-set.git";
+      rev = "4294d5d51f896e54de3f01c12ed35a46d9451258";
+      hash = "sha256-oVztgqlGB8qkOlJU7HCWXT8BBZLAHHajdws6FIe33XA=";
+    }} $out/share/icons/yet-another-monochrome-icon-set
+    chmod -R u+w $out/share/icons
+  '';
+
   # A featherweight icon theme that inherits Papirus-Dark and overrides only
   # the folder faces, rather than a recoloured copy of the whole 200MB tree
   # per wallpaper. Papirus-Dark delegates its size dirs to ../Papirus by
@@ -304,8 +330,12 @@ let
       {
         echo "[Icon Theme]"
         echo "Name=Papirus-Fred"
-        echo "Comment=Papirus-Dark with ${color} folders"
+        echo "Comment=YAMIS app icons with ${color} Papirus folders"
-        echo "Inherits=Papirus-Dark,Papirus,hicolor"
+        # YAMIS first, so every app it covers wins; its own index.theme falls
+        # through to Papirus-Dark for the rest. Papirus is repeated here
+        # anyway — an upstream edit to YAMIS's Inherits must not be able to
+        # break the fallback that the folder overrides below depend on.
+        echo "Inherits=yet-another-monochrome-icon-set,Papirus-Dark,Papirus,hicolor"
         printf 'Directories='
         first=1
         for size in $sizes; do
@@ -575,6 +605,11 @@ in
       apply = themeApply;
     };
 
+    # Papirus-Fred inherits this by name, so it has to be on the icon search
+    # path for the lookup to resolve — installing the theme is what makes the
+    # Inherits= line above mean anything.
+    environment.systemPackages = [ yamisIcons ];
+
     home-manager.users.fred = { config, lib, pkgs, osConfig, ... }: {
       # These targets write build-time files that theme-apply replaces at
       # runtime; leaving them on means stylix and the switcher fight over the