Add extra headers for OpenAI (#1615)

lua/avante/config.lua

@@ -557,6 +557,7 @@ end
 
 M.BASE_PROVIDER_KEYS = {
   "endpoint",
+  "extra_headers",
   "model",
   "deployment",
   "api_version",

lua/avante/providers/openai.lua

@@ -278,6 +278,12 @@ function M:parse_curl_args(prompt_opts)
     ["Content-Type"] = "application/json",
   }
 
+  if provider_conf.extra_headers then
+    for key, value in pairs(provider_conf.extra_headers) do
+      headers[key] = value
+    end
+  end
+
   if P.env.require_api_key(provider_conf) then
     local api_key = self.parse_api_key()
     if api_key == nil then

lua/avante/types.lua

@@ -200,6 +200,7 @@ vim.g.avante_login = vim.g.avante_login
 ---
 ---@class AvanteDefaultBaseProvider: table<string, any>
 ---@field endpoint? string
+---@field extra_headers? table<string, any>
 ---@field model? string
 ---@field local? boolean
 ---@field proxy? string