remove theme sync

lua/chadrc.lua

@@ -2,19 +2,6 @@
 -- https://github.com/NvChad/ui/blob/v2.5/lua/nvconfig.lua
 -- Please read that file to know all available options :(
 
--- Get system theme from darkman
-local function get_system_theme()
-  local handle = io.popen("darkman get 2>/dev/null")
-  if handle then
-    local result = handle:read("*a")
-    handle:close()
-    if result and result:match("light") then
-      return "onenord_light"
-    end
-  end
-  return "onenord"  -- default dark theme
-end
-
 ---@type ChadrcConfig
 local M = {
   ui = {
@@ -23,7 +10,7 @@ local M = {
     },
   },
   base46 = {
-    theme = get_system_theme(),
+    theme = "onenord",
   },
 
   nvdash = {