feat: add MiniMax provider support to OpenAI compatible plugin

- Add MiniMax provider configuration to ProviderMap
- Set MiniMax base URL to api.minimaxi.com/v1
- Configure MiniMax with ImplementsResponses as false
- Add test case for MiniMax provider validation

internal/plugins/ai/openai_compatible/providers_config.go

@@ -165,6 +165,11 @@ var ProviderMap = map[string]ProviderConfig{
 		BaseURL:             "http://localhost:4000",
 		ImplementsResponses: false,
 	},
+	"MiniMax": {
+		Name:                "MiniMax",
+		BaseURL:             "https://api.minimaxi.com/v1",
+		ImplementsResponses: false,
+	},
 	"Mistral": {
 		Name:                "Mistral",
 		BaseURL:             "https://api.mistral.ai/v1",

internal/plugins/ai/openai_compatible/providers_config_test.go

@@ -30,6 +30,11 @@ func TestCreateClient(t *testing.T) {
 			provider: "Abacus",
 			exists:   true,
 		},
+		{
+			name:     "Existing provider - MiniMax",
+			provider: "MiniMax",
+			exists:   true,
+		},
 		{
 			name:     "Non-existent provider",
 			provider: "NonExistent",