fix: 修复时区问题 - FixedZone 兜底 + Dockerfile 复制完整 zoneinfo

1. ppanel.go: LoadLocation 失败时用 FixedZone("CST", +8h) 兜底
2. Dockerfile: 复制完整 /usr/share/zoneinfo 目录，确保 go-sql-driver 也能加载 Asia/Shanghai

Co-Authored-By: claude-flow <ruv@ruv.net>

Dockerfile

@@ -28,7 +28,7 @@ FROM scratch
 
 # Copy CA certificates and timezone data
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
-COPY --from=builder /usr/share/zoneinfo/Asia/Shanghai /usr/share/zoneinfo/Asia/Shanghai
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
 
 ENV TZ=Asia/Shanghai
 

ppanel.go

@@ -8,12 +8,13 @@ import (
 
 func init() {
 	// Ensure time.Local matches DSN loc=Asia/Shanghai.
-	// In scratch Docker images, Go defaults to UTC even with TZ set,
-	// causing time range queries to shift by 8 hours.
+	// In scratch Docker images, LoadLocation may fail due to missing zoneinfo,
+	// so fall back to FixedZone as a guaranteed alternative.
 	loc, err := time.LoadLocation("Asia/Shanghai")
-	if err == nil {
-		time.Local = loc
+	if err != nil {
+		loc = time.FixedZone("CST", 8*3600)
 	}
+	time.Local = loc
 }
 
 func main() {