Improve code quality: remove unused code, simplify random, dynamic timestamps

- Remove unused buildToolCalls() function (logic is inlined)\n- Simplify randomString() using global rand (Go 1.20+)\n- Use dynamic timestamps instead of hardcoded 1234567890\n- Add time import to converter.go

converter.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"strings"
+	"time"
 )
 
 // ConvertOpenAIRequest converts an OpenAI ChatCompletionRequest to Anthropic format
@@ -136,7 +137,7 @@ func ConvertAnthropicResponse(resp *AnthropicResponse, model string) *ChatComple
 	response := &ChatCompletionResponse{
 		ID:      resp.Id,
 		Object:  "chat.completion",
-		Created: 1234567890,
+		Created: time.Now().Unix(),
 		Model:   model,
 		Choices: make([]Choice, 0),
 		Usage: Usage{
@@ -210,22 +211,3 @@ func mapStopReason(reason string) string {
 		return "stop"
 	}
 }
-
-// buildToolCalls builds OpenAI ToolCall slice from Anthropic ContentBlocks
-func buildToolCalls(content []ContentBlock) []ToolCall {
-	var toolCalls []ToolCall
-	for _, block := range content {
-		if block.Type == "tool_use" {
-			inputJSON, _ := json.Marshal(block.Input)
-			toolCalls = append(toolCalls, ToolCall{
-				ID:   block.Id,
-				Type: "function",
-				Function: FunctionCall{
-					Name:      block.Name,
-					Arguments: string(inputJSON),
-				},
-			})
-		}
-	}
-	return toolCalls
-}

handler.go

@@ -253,9 +253,8 @@ func writeError(w http.ResponseWriter, code int, message, errType, errCode strin
 func randomString(n int) string {
 	const letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
 	b := make([]byte, n)
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	for i := range b {
-		b[i] = letters[r.Intn(len(letters))]
+		b[i] = letters[rand.Intn(len(letters))]
 	}
 	return string(b)
 }