fix: remove duplicate kimi provider and fix test locale

Remove the duplicate kimi provider entry introduced by overlapping PRs
(#130 and #134). Keep the Kimi Moonshot API entry with MOONSHOT_API_KEY.

Set LC_ALL=C in Makefile test target to ensure git outputs English
messages regardless of system locale.

Makefile

@@ -30,7 +30,7 @@ build:
 	$(GO) build -ldflags "$(LD_FLAGS)" -o $(DIST_DIR)/$(BINARY_NAME) ./cmd/opencodereview
 
 test:
-	$(GO) test -v -race -count=1 ./...
+	LC_ALL=C $(GO) test -v -race -count=1 ./...
 
 clean:
 	rm -rf $(DIST_DIR)

internal/llm/providers.go

@@ -130,18 +130,6 @@ var registry = []Provider{
 			"MiniMax-M2.5-highspeed",
 		},
 	},
-	{
-		Name:        "kimi",
-		DisplayName: "Kimi API",
-		Protocol:    "openai",
-		BaseURL:     "https://api.moonshot.cn/v1",
-		EnvVar:      "KIMI_API_KEY",
-		Models: []string{
-			"kimi-k2.5",
-			"kimi-k2.6",
-			"kimi-k2.7-code",
-		},
-	},
 }
 
 var registryMap map[string]Provider

internal/llm/providers_test.go

@@ -40,7 +40,7 @@ func TestListProviders_Order(t *testing.T) {
 	if len(providers) < 3 {
 		t.Fatalf("expected at least 3 providers, got %d", len(providers))
 	}
-	expected := []string{"anthropic", "dashscope", "deepseek", "kimi", "mimo", "minimax", "openai", "z-ai"}
+	expected := []string{"anthropic", "dashscope", "deepseek", "kimi", "mimo", "minimax", "openai", "volcengine", "z-ai"}
 	if len(providers) != len(expected) {
 		t.Fatalf("expected %d providers, got %d", len(expected), len(providers))
 	}