重构日志与可观测性体系

新增单行文本编码器与结构化 GORM 日志，统一错误记录与请求日志策略，收紧日志文件权限并修复按天切分与压缩，支付回调参数脱敏，生产强制阿里云短信，RequestID 校验防注入，日志文案中文化。

backend/internal/logging/daily_writer.go

@@ -2,6 +2,7 @@ package logging
 
 import (
 	"compress/gzip"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -21,6 +22,12 @@ type dailyWriter struct {
 	file       *os.File
 }
 
+func (w *dailyWriter) Open() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	return w.rotateIfNeeded(time.Now().In(w.location))
+}
+
 func newDailyWriter(dir string, prefix string, location *time.Location, retainDays int) *dailyWriter {
 	if retainDays < 0 {
 		retainDays = 0
@@ -59,51 +66,79 @@ func (w *dailyWriter) rotateIfNeeded(now time.Time) error {
 		return nil
 	}
 
-	if err := os.MkdirAll(w.dir, 0o755); err != nil {
+	if err := os.MkdirAll(w.dir, 0o700); err != nil {
+		return err
+	}
+	if err := os.Chmod(w.dir, 0o700); err != nil {
 		return err
 	}
 
-	prevDay := w.day
 	if w.file != nil {
-		_ = w.file.Close()
+		if err := w.file.Close(); err != nil {
+			return err
+		}
 		w.file = nil
 	}
 
 	path := filepath.Join(w.dir, fmt.Sprintf("%s-%s.log", w.prefix, day))
-	file, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+	file, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o600)
 	if err != nil {
 		return err
 	}
+	if err := file.Chmod(0o600); err != nil {
+		_ = file.Close()
+		return err
+	}
 	w.file = file
 	w.day = day
 
-	// 异步压缩昨日日志并清理过期文件，避免阻塞业务写路径
-	if prevDay != "" && prevDay != day {
-		go w.maintain(prevDay, now)
-	} else {
-		// 进程启动或首写：尝试压缩昨天 + 清理过期
-		yesterday := now.AddDate(0, 0, -1).Format("2006-01-02")
-		go w.maintain(yesterday, now)
-	}
+	// 异步补压缩全部历史日志并清理过期文件，避免漏掉停机期间的日期。
+	go w.maintain(now)
 	return nil
 }
 
-func (w *dailyWriter) maintain(prevDay string, now time.Time) {
-	if prevDay != "" {
-		_ = w.compressDay(prevDay)
+func (w *dailyWriter) maintain(now time.Time) {
+	if err := w.compressHistorical(now); err != nil {
+		writeMaintenanceError(err)
 	}
 	if w.retainDays > 0 {
-		_ = w.purgeOlderThan(now)
+		if err := w.purgeOlderThan(now); err != nil {
+			writeMaintenanceError(err)
+		}
 	}
 }
 
+func (w *dailyWriter) compressHistorical(now time.Time) error {
+	entries, err := os.ReadDir(w.dir)
+	if err != nil {
+		return err
+	}
+	today := now.In(w.location).Format("2006-01-02")
+	for _, entry := range entries {
+		day, ok := w.dayFromFilename(entry.Name(), ".log")
+		if !ok || day >= today {
+			continue
+		}
+		if err := w.compressDay(day); err != nil {
+			return fmt.Errorf("压缩 %s 日志失败: %w", day, err)
+		}
+	}
+	return nil
+}
+
 func (w *dailyWriter) compressDay(day string) error {
 	srcPath := filepath.Join(w.dir, fmt.Sprintf("%s-%s.log", w.prefix, day))
 	dstPath := srcPath + ".gz"
 	if _, err := os.Stat(dstPath); err == nil {
-		// 已压缩则删除明文（若仍存在）
-		_ = os.Remove(srcPath)
-		return nil
+		if err := validateGzip(dstPath); err == nil {
+			if err := os.Remove(srcPath); err != nil && !os.IsNotExist(err) {
+				return err
+			}
+			return nil
+		}
+		if err := os.Remove(dstPath); err != nil {
+			return err
+		}
 	}
 	src, err := os.Open(srcPath)
 	if err != nil {
@@ -114,32 +149,58 @@ func (w *dailyWriter) compressDay(day string) error {
 	}
 	defer src.Close()
 
-	dst, err := os.OpenFile(dstPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o644)
+	dst, err := os.CreateTemp(w.dir, "."+filepath.Base(dstPath)+".tmp-*")
 	if err != nil {
 		return err
 	}
+	tmpPath := dst.Name()
+	defer func() { _ = os.Remove(tmpPath) }()
+	if err := dst.Chmod(0o600); err != nil {
+		_ = dst.Close()
+		return err
+	}
 	gz := gzip.NewWriter(dst)
 	if _, err := io.Copy(gz, src); err != nil {
 		_ = gz.Close()
 		_ = dst.Close()
-		_ = os.Remove(dstPath)
 		return err
 	}
 	if err := gz.Close(); err != nil {
 		_ = dst.Close()
-		_ = os.Remove(dstPath)
+		return err
+	}
+	if err := dst.Sync(); err != nil {
+		_ = dst.Close()
 		return err
 	}
 	if err := dst.Close(); err != nil {
 		return err
 	}
+	if err := os.Rename(tmpPath, dstPath); err != nil {
+		return err
+	}
 	return os.Remove(srcPath)
 }
 
+func validateGzip(path string) error {
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	reader, err := gzip.NewReader(file)
+	if err != nil {
+		return err
+	}
+	_, copyErr := io.Copy(io.Discard, reader)
+	closeErr := reader.Close()
+	return errors.Join(copyErr, closeErr)
+}
+
 func (w *dailyWriter) purgeOlderThan(now time.Time) error {
 	// 按「日历天」比较：保留最近 retainDays 天（含当天），更早的 .log / .log.gz 删除。
 	today := time.Date(now.In(w.location).Year(), now.In(w.location).Month(), now.In(w.location).Day(), 0, 0, 0, 0, w.location)
-	cutoff := today.AddDate(0, 0, -w.retainDays) // day < cutoff 才删除；retainDays=2 且今天 12 号 → 删除 10 号之前
+	cutoff := today.AddDate(0, 0, -(w.retainDays - 1))
 	entries, err := os.ReadDir(w.dir)
 	if err != nil {
 		return err
@@ -150,10 +211,10 @@ func (w *dailyWriter) purgeOlderThan(now time.Time) error {
 			continue
 		}
 		name := entry.Name()
-		if !strings.HasPrefix(name, prefix) {
+		if !strings.HasPrefix(name, prefix) ||
+			(!strings.HasSuffix(name, ".log") && !strings.HasSuffix(name, ".log.gz")) {
 			continue
 		}
-		// app-2026-07-11.log 或 app-2026-07-11.log.gz
 		rest := strings.TrimPrefix(name, prefix)
 		rest = strings.TrimSuffix(rest, ".gz")
 		rest = strings.TrimSuffix(rest, ".log")
@@ -162,8 +223,26 @@ func (w *dailyWriter) purgeOlderThan(now time.Time) error {
 			continue
 		}
 		if day.Before(cutoff) {
-			_ = os.Remove(filepath.Join(w.dir, name))
+			if err := os.Remove(filepath.Join(w.dir, name)); err != nil && !os.IsNotExist(err) {
+				return err
+			}
 		}
 	}
 	return nil
 }
+
+func (w *dailyWriter) dayFromFilename(name string, suffix string) (string, bool) {
+	prefix := w.prefix + "-"
+	if !strings.HasPrefix(name, prefix) || !strings.HasSuffix(name, suffix) {
+		return "", false
+	}
+	day := strings.TrimSuffix(strings.TrimPrefix(name, prefix), suffix)
+	if _, err := time.ParseInLocation("2006-01-02", day, w.location); err != nil {
+		return "", false
+	}
+	return day, true
+}
+
+func writeMaintenanceError(err error) {
+	_, _ = fmt.Fprintf(os.Stderr, "%s | ERROR | 日志维护失败 | error=%q\n", time.Now().Format("2006-01-02 15:04:05.000"), err.Error())
+}