hm: isolate tmux-sessionizer configuration

nix/configurations/vanadium.nix

@@ -163,6 +163,8 @@ in
           ../homeModules/common/tealdeer.nix
           ../homeModules/common/user-nixconf.nix
 
+          ../homeModules/extra/tmux-fish-integration.nix
+
           #
           # Extern modules
           #

nix/homeModules/common/fish/default.nix

@@ -12,20 +12,7 @@ in {
     ./aliasesAbbrs.nix
   ];
 
-  #
+  # TODO: do not set this here
-  # tmux sessionizer
-  #
-  home.sessionVariables = lib.mapAttrs (_: path: config.home.homeDirectory + "/${path}") {
-    REPO_PATH = "r";
-    PLAYGROUND_PATH = "pg";
-    WORKTREE_PATH = "wt";
-  };
-  programs.direnv.config.whitelist.prefix = [(config.home.sessionVariables.REPO_PATH + "/leana8959")];
-  programs.tmux.extraConfig = lib.mkBefore ''
-    # sessionizer binds
-    bind -n C-f run-shell "tmux new-window tmux-sessionizer"
-    bind s run-shell "tmux-last"
-  '';
   programs.kitty.settings.shell = ''${fishExe}'';
 
   #

nix/homeModules/extra/tmux-fish-integration.nix

@@ -0,0 +1,30 @@
+# This module integrates tmux with fish
+{pkgs, lib, config, ...}: {
+
+  assertions = [
+    { assertion = config.programs.fish.enable;
+      message = "Should have fish enabled";
+    }
+    { assertion = config.programs.tmux.enable;
+      message = "Should have tmux enabled";
+    }
+  ];
+
+  home.sessionVariables = lib.mapAttrs (_: path: config.home.homeDirectory + "/${path}") {
+    REPO_PATH = "r";
+    PLAYGROUND_PATH = "pg";
+    WORKTREE_PATH = "wt";
+  };
+
+  programs.direnv.config.whitelist.prefix = [(config.home.sessionVariables.REPO_PATH + "/leana8959")];
+  programs.tmux.extraConfig = lib.mkBefore ''
+    # sessionizer binds
+    bind -n C-f run-shell "tmux new-window tmux-sessionizer"
+    bind s run-shell "tmux-last"
+  '';
+
+  home.packages = with pkgs; [
+    tmux-sessionizer
+  ];
+
+}