Add token-stats-hook Go module and update README

hooks/token-stats-hook/README.md

@@ -0,0 +1,39 @@
+# token-stats-hook
+
+Claude Code Stop hook：每次会话结束时自动将 token 用量快照追加到 `~/.claude/token-stats-backup.jsonl`。
+
+用 Go 编写，编译为二进制，启动时间 <5ms。
+
+## 安装
+
+```bash
+cd hooks/token-stats-hook
+go build -o ~/.claude/token-stats-hook-bin .
+```
+
+然后在 `~/.claude/settings.json` 中加入：
+
+```json
+{
+  "hooks": {
+    "Stop": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "~/.claude/token-stats-hook-bin 2>/dev/null || true"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+## 备份格式
+
+每行一条 JSON 记录：
+
+```json
+{"timestamp":"2026-04-18T02:03:11Z","date":"2026-04-18","user":"charles","input":12861,"output":176499,"cache_write":1352380,"cache_read":15525643,"actual":189360}
+```

hooks/token-stats-hook/go.mod

@@ -0,0 +1,3 @@
+module token-stats-hook
+
+go 1.18

hooks/token-stats-hook/main.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+type usage struct {
+	InputTokens               int `json:"input_tokens"`
+	OutputTokens              int `json:"output_tokens"`
+	CacheCreationInputTokens  int `json:"cache_creation_input_tokens"`
+	CacheReadInputTokens      int `json:"cache_read_input_tokens"`
+}
+
+type message struct {
+	Usage usage `json:"usage"`
+}
+
+type entry struct {
+	Message message `json:"message"`
+}
+
+type record struct {
+	Timestamp  string `json:"timestamp"`
+	Date       string `json:"date"`
+	User       string `json:"user"`
+	Input      int    `json:"input"`
+	Output     int    `json:"output"`
+	CacheWrite int    `json:"cache_write"`
+	CacheRead  int    `json:"cache_read"`
+	Actual     int    `json:"actual"`
+}
+
+func main() {
+	home, _ := os.UserHomeDir()
+	user := os.Getenv("USER")
+	if user == "" {
+		user = filepath.Base(home)
+	}
+
+	var total record
+	pattern := filepath.Join(home, ".claude", "projects", "**", "*.jsonl")
+	matches, _ := filepath.Glob(pattern)
+
+	// filepath.Glob doesn't support **, so walk manually
+	projectsDir := filepath.Join(home, ".claude", "projects")
+	filepath.Walk(projectsDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil || info.IsDir() || filepath.Ext(path) != ".jsonl" {
+			return nil
+		}
+		_ = matches
+		f, err := os.Open(path)
+		if err != nil {
+			return nil
+		}
+		defer f.Close()
+
+		scanner := bufio.NewScanner(f)
+		scanner.Buffer(make([]byte, 1024*1024), 1024*1024)
+		for scanner.Scan() {
+			var e entry
+			if json.Unmarshal(scanner.Bytes(), &e) == nil {
+				u := e.Message.Usage
+				total.Input += u.InputTokens
+				total.Output += u.OutputTokens
+				total.CacheWrite += u.CacheCreationInputTokens
+				total.CacheRead += u.CacheReadInputTokens
+			}
+		}
+		return nil
+	})
+
+	now := time.Now().UTC()
+	total.Timestamp = now.Format(time.RFC3339)
+	total.Date = now.Format("2006-01-02")
+	total.User = user
+	total.Actual = total.Input + total.Output
+
+	backup := filepath.Join(home, ".claude", "token-stats-backup.jsonl")
+	f, err := os.OpenFile(backup, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		os.Exit(1)
+	}
+	defer f.Close()
+
+	line, _ := json.Marshal(total)
+	fmt.Fprintf(f, "%s\n", line)
+}