feat(nix): enhance WezTerm and Fish configuration

- Enabled scroll bar and added conditional fullscreen key handling in `wezterm.lua` for better usability.
- Updated Fish shell to set global `LESS` mouse support for improved navigation.

homes/x86_64-linux/harald@amd/default.nix

@@ -75,8 +75,29 @@
   xdg.configFile."wezterm/wezterm.lua".text = ''
     local wezterm = require("wezterm")
     local config = wezterm.config_builder()
+    local act = wezterm.action
 
     config.enable_kitty_keyboard = true
+    config.enable_scroll_bar = true
+
+    local function action_unless_fullscreen(action, key)
+      return wezterm.action_callback(function(win, pane)
+        if pane:is_alt_screen_active() then
+          -- a program is full screen, passthrough the key
+          win:perform_action(act.SendKey { key = key, mods = 'NONE' }, pane)
+        else
+          -- do the action
+          win:perform_action(action, pane)
+        end
+      end)
+    end
+
+    -- config.keys = {
+    --   { key = 'PageUp', mods = 'NONE', action = action_unless_fullscreen(act.ScrollByPage(-0.5), 'PageUp') },
+    --   { key = 'PageDown', mods = 'NONE', action = action_unless_fullscreen(act.ScrollByPage(0.5), 'PageDown') },
+    -- }
+
+    config.term = 'wezterm'
 
     return config
   '';