feat: add model name to sidebar

Author: T0nd0Tara

lua/avante/config.lua

@@ -683,6 +683,7 @@ M._defaults = {
       enabled = true, -- true, false to enable/disable the header
       align = "center", -- left, center, right for title
       rounded = true,
+      include_model = false,
     },
     spinner = {
       editing = {

lua/avante/sidebar.lua

@@ -1007,6 +1007,9 @@ function Sidebar:render_header(winid, bufnr, header_text, hl, reverse_hl)
   else
     header_text = format_segment(" " .. header_text .. " ", hl)
   end
+  if Config.windows.sidebar_header.include_model then
+    header_text = header_text .. " " .. Config.providers[Config.provider].model
+  end
 
   local winbar_text
   if Config.windows.sidebar_header.align == "left" then