feat(nvim): add cheap openai provider for avante

modules/programs/nvim/new_plugins/avante.nix

@@ -19,14 +19,28 @@ in
         require("avante_lib").load()
         require("avante").setup({
           provider = "openai",
-          auto_suggestions_provider = "openai",
+          auto_suggestions_provider = "openai-cheap",
           behaviour = {
-            -- auto_suggestions = true,
+            auto_suggestions = false,
           },
           openai = {
             model = "gpt-4o",
-            api_key_name = "cmd:cat /run/agenix/openai"
-          }
+            api_key_name = "cmd:cat /run/agenix/openai",
+          },
+          vendors = {
+            ---@type AvanteProvider
+            ["openai-cheap"] = {
+              model = "gpt-4o-mini",
+              api_key_name = "cmd:cat /run/agenix/openai",
+              endpoint = "https://api.openai.com/v1",
+              parse_curl_args = function(opts, code_opts)
+                return require("avante.providers").openai.parse_curl_args(opts, code_opts)
+              end,
+              parse_response_data = function(data_stream, event_state, opts)
+                return require("avante.providers").openai.parse_response(data_stream, event_state, opts)
+              end
+            },
+          },
         })
       '';
       plugins.dressing.enable = true;