feat: add MCP tools registration to LLM service

- Add RegisterTools method to ILLMService interface
- Create shared MCP to eino tool converter
- Auto-register built-in uixt tools in XTDriver initialization
- Refactor MCPHost to use shared converter
- Add comprehensive test coverage for tool conversion

This enables doubao-1.5-thinking-vision-pro model to access
MCP tools through function calling mechanism.

uixt/ai/ai.go

@@ -3,6 +3,7 @@ package ai
 import (
 	"context"
 
+	"github.com/cloudwego/eino/schema"
 	"github.com/httprunner/httprunner/v5/uixt/option"
 )
 
@@ -10,6 +11,8 @@ import (
 type ILLMService interface {
 	Call(ctx context.Context, opts *PlanningOptions) (*PlanningResult, error)
 	Assert(ctx context.Context, opts *AssertOptions) (*AssertionResult, error)
+	// RegisterTools registers tools for function calling
+	RegisterTools(tools []*schema.ToolInfo) error
 }
 
 func NewLLMService(modelType option.LLMServiceType) (ILLMService, error) {
@@ -49,3 +52,12 @@ func (c *combinedLLMService) Call(ctx context.Context, opts *PlanningOptions) (*
 func (c *combinedLLMService) Assert(ctx context.Context, opts *AssertOptions) (*AssertionResult, error) {
 	return c.asserter.Assert(ctx, opts)
 }
+
+// RegisterTools registers tools for function calling
+func (c *combinedLLMService) RegisterTools(tools []*schema.ToolInfo) error {
+	// Only register tools to planner since asserter doesn't need tools
+	if planner, ok := c.planner.(*Planner); ok {
+		return planner.RegisterTools(tools)
+	}
+	return nil
+}