fix: rename duplicate function name

Author: pxwg

lua/CopilotChat/client.lua

@@ -312,9 +312,9 @@ function Client:ask(opts)
     local provider_name = 'copilot'
     local provider = self:get_providers():get(provider_name)
 
-    if provider and provider.select_model then
+    if provider and provider.route_model then
       local headers = self:authenticate(provider_name)
-      local selected_model, err = provider.select_model(headers, { 'auto' })
+      local selected_model, err = provider.route_model(headers, { 'auto' })
 
       if selected_model then
         opts.model = selected_model

lua/CopilotChat/config/providers.lua

@@ -513,7 +513,7 @@ end
 local M = {}
 
 M.copilot = {
-  select_model = function(headers, hints)
+  route_model = function(headers, hints)
     hints = hints or { 'auto' }
     local token = headers['Authorization'] and headers['Authorization']:gsub('^Bearer%s+', '')
     if not token then