feat(model): 双协议 LLM Provider（AnthropicChNativeAdapter /v1/messages + tool_use.input→Args 直接映射 + 流式重组）+ Provider 感知工厂/路由 + LLM_PROVIDER/anthropic 配置（OpenAI 兼容保留）

internal/runtime/model/router.go

@@ -2,11 +2,16 @@ package model
 
 // Router maps roles to model names. An unknown role resolves to the configured
 // default model. When a request carries image content and a vision model is
-// configured, the request routes to the vision model.
+// configured, the request routes to the vision model. A Router also carries a
+// provider per role (defaulting to the global provider) so a multi-vendor
+// deployment can pair a role's model with the correct protocol; the provider
+// selection is surfaced via RouteProvider.
 type Router struct {
-	defaultModel string
-	byRole       map[Role]string
-	visionModel  string
+	defaultModel    string
+	byRole          map[Role]string
+	visionModel     string
+	defaultProvider string
+	providerByRole  map[Role]string
 }
 
 // RouterOption configures a Router.
@@ -22,10 +27,28 @@ func WithVisionModel(model string) RouterOption {
 	return func(r *Router) { r.visionModel = model }
 }
 
+// WithDefaultProvider sets the provider returned by RouteProvider for roles with
+// no explicit binding. It defaults to openai.
+func WithDefaultProvider(provider string) RouterOption {
+	return func(r *Router) { r.defaultProvider = provider }
+}
+
+// WithRoleProvider binds a provider to a role, so a multi-vendor deployment can
+// route a role to a different vendor's protocol (e.g. one role on anthropic, one
+// on openai). Pair it with WithRoleModel for the role's model name.
+func WithRoleProvider(role Role, provider string) RouterOption {
+	return func(r *Router) { r.providerByRole[role] = provider }
+}
+
 // NewRouter builds a Router with a default model applied to any role that has
 // no explicit binding.
 func NewRouter(defaultModel string, opts ...RouterOption) *Router {
-	r := &Router{defaultModel: defaultModel, byRole: map[Role]string{}}
+	r := &Router{
+		defaultModel:    defaultModel,
+		byRole:          map[Role]string{},
+		defaultProvider: ProviderOpenAI,
+		providerByRole:  map[Role]string{},
+	}
 	for _, o := range opts {
 		o(r)
 	}
@@ -40,6 +63,18 @@ func (r *Router) Route(role Role) string {
 	return r.defaultModel
 }
 
+// RouteProvider returns the provider for a role, falling back to the router's
+// default provider. It is the routing hook for a multi-vendor deployment: each
+// role can carry its own provider+model pairing, and roles without a binding fall
+// back to the global provider. The runtime/loop is expected to build a per-role
+// adapter or chain from this decision (the provider-aware factory is the builder).
+func (r *Router) RouteProvider(role Role) string {
+	if p, ok := r.providerByRole[role]; ok && p != "" {
+		return p
+	}
+	return r.defaultProvider
+}
+
 // RouteRequest picks the model for a request and reports whether the request
 // needs a vision model. When the request carries image content and a vision
 // model is configured, the vision model is returned with needsVision set to