initial commit: Go version of SMS Receiver with fixed template rendering

- Implemented all core features from Python version
- Fixed int64/int type compatibility in template functions
- Added login authentication, SMS receiving, statistics, logs
- Independent database: sms_receiver_go.db
- Fixed frontend display issues for message list and statistics

.gitignore

@@ -0,0 +1,30 @@
+# 编译的二进制文件
+sms-receiver
+sms-receiver-new
+
+# 数据库文件
+*.db
+*.db-shm
+*.db-wal
+
+# 日志文件
+*.log
+nohup.out
+
+# 临时文件
+tmp/
+*.tmp
+
+# Go 相关
+go.sum
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# 备份文件
+*.bak
+*.backup