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

config.yaml

@@ -0,0 +1,34 @@
+# SMS Receiver Go - 配置文件
+app:
+  name: "短信转发接收端"
+  version: "1.0.0"
+
+server:
+  host: "0.0.0.0"
+  port: 28001
+  debug: true
+
+security:
+  enabled: true
+  username: "admin"
+  password: "admin123"
+  session_lifetime: 3600
+  secret_key: "1e81b5f9e5a695eba01e996b14871db8899b08e111cf8252df8aa4c91d1c7144"
+  sign_verify: true
+  sign_max_age: 3600000
+
+sms:
+  max_messages: 10000
+  auto_cleanup: true
+  cleanup_days: 30
+
+database:
+  path: "sms_receiver_go.db"
+
+timezone: "Asia/Shanghai"
+
+api_tokens:
+  - name: "默认配置"
+    token: "default_token"
+    secret: ""
+    enabled: true