Address Copilot review feedback for Kimi/Opencode providers

- Allow APIBase-only config for opencode provider selection (like VLLM)
- Keep moonshot provider on moonshot.cn/v1 default, only use kimi.com/coding/v1 for kimi/kimi-code
- Use url.Parse hostname match for Kimi User-Agent check instead of strings.Contains
- Add opencode to DefaultAPIBase test cases in factory_provider_test.go
- Add opencode migration tests (full config + APIBase-only) in migration_test.go
- Update AllProviders test count to include opencode (18 -> 19)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/config/migration_test.go

@@ -132,14 +132,15 @@ func TestConvertProvidersToModelList_AllProviders(t *testing.T) {
 			Antigravity:   ProviderConfig{AuthMethod: "oauth"},
 			Qwen:          ProviderConfig{APIKey: "key17"},
 			Mistral:       ProviderConfig{APIKey: "key18"},
+			Opencode:      ProviderConfig{APIKey: "key19"},
 		},
 	}
 
 	result := ConvertProvidersToModelList(cfg)
 
-	// All 18 providers should be converted
-	if len(result) != 18 {
-		t.Errorf("len(result) = %d, want 18", len(result))
+	// All 19 providers should be converted
+	if len(result) != 19 {
+		t.Errorf("len(result) = %d, want 19", len(result))
 	}
 }
 
@@ -551,6 +552,65 @@ func TestBuildModelWithProtocol_DifferentPrefix(t *testing.T) {
 	}
 }
 
+func TestConvertProvidersToModelList_Opencode(t *testing.T) {
+	cfg := &Config{
+		Providers: ProvidersConfig{
+			Opencode: ProviderConfig{
+				APIKey:         "oc-test-key",
+				APIBase:        "https://custom.opencode.ai/v1",
+				Proxy:          "http://proxy:9090",
+				RequestTimeout: 60,
+			},
+		},
+	}
+
+	result := ConvertProvidersToModelList(cfg)
+
+	if len(result) != 1 {
+		t.Fatalf("len(result) = %d, want 1", len(result))
+	}
+
+	mc := result[0]
+	if mc.ModelName != "opencode" {
+		t.Errorf("ModelName = %q, want %q", mc.ModelName, "opencode")
+	}
+	if mc.Model != "opencode/auto" {
+		t.Errorf("Model = %q, want %q", mc.Model, "opencode/auto")
+	}
+	if mc.APIKey != "oc-test-key" {
+		t.Errorf("APIKey = %q, want %q", mc.APIKey, "oc-test-key")
+	}
+	if mc.APIBase != "https://custom.opencode.ai/v1" {
+		t.Errorf("APIBase = %q, want %q", mc.APIBase, "https://custom.opencode.ai/v1")
+	}
+	if mc.Proxy != "http://proxy:9090" {
+		t.Errorf("Proxy = %q, want %q", mc.Proxy, "http://proxy:9090")
+	}
+	if mc.RequestTimeout != 60 {
+		t.Errorf("RequestTimeout = %d, want %d", mc.RequestTimeout, 60)
+	}
+}
+
+func TestConvertProvidersToModelList_Opencode_APIBaseOnly(t *testing.T) {
+	cfg := &Config{
+		Providers: ProvidersConfig{
+			Opencode: ProviderConfig{
+				APIBase: "https://custom.opencode.ai/v1",
+			},
+		},
+	}
+
+	result := ConvertProvidersToModelList(cfg)
+
+	if len(result) != 1 {
+		t.Fatalf("len(result) = %d, want 1 (APIBase-only should create entry)", len(result))
+	}
+
+	if result[0].ModelName != "opencode" {
+		t.Errorf("ModelName = %q, want %q", result[0].ModelName, "opencode")
+	}
+}
+
 // Test for legacy config with protocol prefix in model name
 func TestConvertProvidersToModelList_LegacyModelWithProtocolPrefix(t *testing.T) {
 	cfg := &Config{

pkg/providers/factory.go

@@ -182,7 +182,7 @@ func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
 				}
 			}
 		case "opencode":
-			if cfg.Providers.Opencode.APIKey != "" {
+			if cfg.Providers.Opencode.APIKey != "" || cfg.Providers.Opencode.APIBase != "" {
 				sel.apiKey = cfg.Providers.Opencode.APIKey
 				sel.apiBase = cfg.Providers.Opencode.APIBase
 				sel.proxy = cfg.Providers.Opencode.Proxy
@@ -196,7 +196,11 @@ func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
 				sel.apiBase = cfg.Providers.Moonshot.APIBase
 				sel.proxy = cfg.Providers.Moonshot.Proxy
 				if sel.apiBase == "" {
-					sel.apiBase = "https://api.kimi.com/coding/v1"
+					if providerName == "moonshot" {
+						sel.apiBase = "https://api.moonshot.cn/v1"
+					} else {
+						sel.apiBase = "https://api.kimi.com/coding/v1"
+					}
 				}
 			}
 		case "github_copilot", "copilot":
@@ -219,7 +223,11 @@ func resolveProviderSelection(cfg *config.Config) (providerSelection, error) {
 			sel.apiBase = cfg.Providers.Moonshot.APIBase
 			sel.proxy = cfg.Providers.Moonshot.Proxy
 			if sel.apiBase == "" {
-				sel.apiBase = "https://api.kimi.com/coding/v1"
+				if strings.Contains(lowerModel, "moonshot") || strings.HasPrefix(model, "moonshot/") {
+					sel.apiBase = "https://api.moonshot.cn/v1"
+				} else {
+					sel.apiBase = "https://api.kimi.com/coding/v1"
+				}
 			}
 		case strings.HasPrefix(model, "openrouter/") ||
 			strings.HasPrefix(model, "anthropic/") ||

pkg/providers/factory_provider_test.go

@@ -112,6 +112,7 @@ func TestCreateProviderFromConfig_DefaultAPIBase(t *testing.T) {
 		{"vllm", "vllm"},
 		{"deepseek", "deepseek"},
 		{"ollama", "ollama"},
+		{"opencode", "opencode"},
 	}
 
 	for _, tt := range tests {

pkg/providers/openai_compat/provider.go

@@ -177,7 +177,7 @@ func (p *Provider) Chat(
 		req.Header.Set("Authorization", "Bearer "+p.apiKey)
 	}
 	// Kimi Code API requires a coding agent User-Agent
-	if strings.Contains(p.apiBase, "api.kimi.com") {
+	if parsedURL, parseErr := url.Parse(p.apiBase); parseErr == nil && parsedURL.Hostname() == "api.kimi.com" {
 		req.Header.Set("User-Agent", "KimiCLI/0.77")
 	}