feat(translator): add user metadata generation for Claude transformation requests

- Introduced unique `user_id` metadata generation in OpenAI to Claude transformation functions.
- Utilized `uuid` and `sha256` for deterministic `account`, `session`, and `user` values.
- Embedded `user_id` into request payloads to enhance request tracking and identification.

internal/translator/claude/gemini/claude_gemini_request.go

@@ -8,15 +8,24 @@ package gemini
 import (
 	"bytes"
 	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 	"math/big"
 	"strings"
 
+	"github.com/google/uuid"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 )
 
+var (
+	user    = ""
+	account = ""
+	session = ""
+)
+
 // ConvertGeminiRequestToClaude parses and transforms a Gemini API request into Claude Code API format.
 // It extracts the model name, system instruction, message contents, and tool declarations
 // from the raw JSON request and returns them in the format expected by the Claude Code API.
@@ -37,8 +46,23 @@ import (
 //   - []byte: The transformed request data in Claude Code API format
 func ConvertGeminiRequestToClaude(modelName string, inputRawJSON []byte, stream bool) []byte {
 	rawJSON := bytes.Clone(inputRawJSON)
-	// Base Claude Code API template with default max_tokens value
-	out := `{"model":"","max_tokens":32000,"messages":[]}`
+
+	if account == "" {
+		u, _ := uuid.NewRandom()
+		account = u.String()
+	}
+	if session == "" {
+		u, _ := uuid.NewRandom()
+		session = u.String()
+	}
+	if user == "" {
+		sum := sha256.Sum256([]byte(account + session))
+		user = hex.EncodeToString(sum[:])
+	}
+	userID := fmt.Sprintf("user_%s_account_%s_session_%s", user, account, session)
+
+	// Base Claude message payload
+	out := fmt.Sprintf(`{"model":"","max_tokens":32000,"messages":[],"metadata":{"user_id":"%s"}}`, userID)
 
 	root := gjson.ParseBytes(rawJSON)
 

internal/translator/claude/openai/chat-completions/claude_openai_request.go

@@ -8,14 +8,24 @@ package chat_completions
 import (
 	"bytes"
 	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"math/big"
 	"strings"
 
+	"github.com/google/uuid"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 )
 
+var (
+	user    = ""
+	account = ""
+	session = ""
+)
+
 // ConvertOpenAIRequestToClaude parses and transforms an OpenAI Chat Completions API request into Claude Code API format.
 // It extracts the model name, system instruction, message contents, and tool declarations
 // from the raw JSON request and returns them in the format expected by the Claude Code API.
@@ -36,8 +46,22 @@ import (
 func ConvertOpenAIRequestToClaude(modelName string, inputRawJSON []byte, stream bool) []byte {
 	rawJSON := bytes.Clone(inputRawJSON)
 
+	if account == "" {
+		u, _ := uuid.NewRandom()
+		account = u.String()
+	}
+	if session == "" {
+		u, _ := uuid.NewRandom()
+		session = u.String()
+	}
+	if user == "" {
+		sum := sha256.Sum256([]byte(account + session))
+		user = hex.EncodeToString(sum[:])
+	}
+	userID := fmt.Sprintf("user_%s_account_%s_session_%s", user, account, session)
+
 	// Base Claude Code API template with default max_tokens value
-	out := `{"model":"","max_tokens":32000,"messages":[]}`
+	out := fmt.Sprintf(`{"model":"","max_tokens":32000,"messages":[],"metadata":{"user_id":"%s"}}`, userID)
 
 	root := gjson.ParseBytes(rawJSON)
 

internal/translator/claude/openai/responses/claude_openai-responses_request.go

@@ -3,13 +3,23 @@ package responses
 import (
 	"bytes"
 	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
 	"math/big"
 	"strings"
 
+	"github.com/google/uuid"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 )
 
+var (
+	user    = ""
+	account = ""
+	session = ""
+)
+
 // ConvertOpenAIResponsesRequestToClaude transforms an OpenAI Responses API request
 // into a Claude Messages API request using only gjson/sjson for JSON handling.
 // It supports:
@@ -23,8 +33,22 @@ import (
 func ConvertOpenAIResponsesRequestToClaude(modelName string, inputRawJSON []byte, stream bool) []byte {
 	rawJSON := bytes.Clone(inputRawJSON)
 
+	if account == "" {
+		u, _ := uuid.NewRandom()
+		account = u.String()
+	}
+	if session == "" {
+		u, _ := uuid.NewRandom()
+		session = u.String()
+	}
+	if user == "" {
+		sum := sha256.Sum256([]byte(account + session))
+		user = hex.EncodeToString(sum[:])
+	}
+	userID := fmt.Sprintf("user_%s_account_%s_session_%s", user, account, session)
+
 	// Base Claude message payload
-	out := `{"model":"","max_tokens":32000,"messages":[]}`
+	out := fmt.Sprintf(`{"model":"","max_tokens":32000,"messages":[],"metadata":{"user_id":"%s"}}`, userID)
 
 	root := gjson.ParseBytes(rawJSON)