```

docs(readme): 重构 README 文档结构并补充模块说明

- 重新组织 README 内容，明确划分私有仓库设置、功能模块等章节
- 补充 crypto、cache、database、middleware、queue 和 utils 模块的功能简介
- 统一代码示例格式，增加 bash 和 go 语言标识

feat(crypto): 优化 PKCS7 填充与去填充函数实现

- 新增 PKCS7Padding 和 PKCS7UnPadding 函数的详细注释
- 添加对输入参数的有效性校验，提升健壮性
- 修复可能引发越界 panic 的潜在问题

feat(database): 完善数据库连接及初始化逻辑

- 为 NewDatabase、NewMysql 和 NewPostgres 函数添加完整注释
- 修复 MaxOpenConns 配置未正确赋值的问题
- 在获取 *sql.DB 实例时增加错误处理逻辑
- 支持通过 Init 变量在连接建立后执行自定义初始化函数

feat(go.mod): 初始化项目依赖管理并引入核心组件

- 添加项目所需的主要依赖包，包括 gin、gorm、redis、nats 等
- 引入常用的工具库如 uuid、ulid、gopsutil 等
- 自动拉取并锁定所有间接依赖版本
```

go.mod

@@ -1,3 +1,90 @@
 module git.apinb.com/bsm-sdk/core
 
 go 1.24
+
+require (
+	github.com/allegro/bigcache/v3 v3.1.0
+	github.com/elastic/go-elasticsearch/v8 v8.19.0
+	github.com/gin-contrib/cors v1.7.6
+	github.com/gin-gonic/gin v1.11.0
+	github.com/google/uuid v1.6.0
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.2
+	github.com/nats-io/nats.go v1.45.0
+	github.com/oklog/ulid/v2 v2.1.1
+	github.com/redis/go-redis/v9 v9.14.0
+	github.com/shirou/gopsutil v2.21.11+incompatible
+	go.etcd.io/etcd/client/pkg/v3 v3.6.5
+	go.etcd.io/etcd/client/v3 v3.6.5
+	google.golang.org/grpc v1.75.1
+	gopkg.in/yaml.v3 v3.0.1
+	gorm.io/driver/mysql v1.6.0
+	gorm.io/driver/postgres v1.6.0
+	gorm.io/gorm v1.31.0
+)
+
+require (
+	filippo.io/edwards25519 v1.1.0 // indirect
+	github.com/bytedance/sonic v1.14.0 // indirect
+	github.com/bytedance/sonic/loader v0.3.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/cloudwego/base64x v0.1.6 // indirect
+	github.com/coreos/go-semver v0.3.1 // indirect
+	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/elastic/elastic-transport-go/v8 v8.7.0 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.9 // indirect
+	github.com/gin-contrib/sse v1.1.0 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/go-ole/go-ole v1.2.6 // indirect
+	github.com/go-playground/locales v0.14.1 // indirect
+	github.com/go-playground/universal-translator v0.18.1 // indirect
+	github.com/go-playground/validator/v10 v10.27.0 // indirect
+	github.com/go-sql-driver/mysql v1.8.1 // indirect
+	github.com/goccy/go-json v0.10.5 // indirect
+	github.com/goccy/go-yaml v1.18.0 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/pgx/v5 v5.6.0 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	github.com/jinzhu/inflection v1.0.0 // indirect
+	github.com/jinzhu/now v1.1.5 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/klauspost/compress v1.18.0 // indirect
+	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
+	github.com/leodido/go-urn v1.4.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/nats-io/nkeys v0.4.11 // indirect
+	github.com/nats-io/nuid v1.0.1 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/quic-go/qpack v0.5.1 // indirect
+	github.com/quic-go/quic-go v0.54.0 // indirect
+	github.com/tklauser/go-sysconf v0.3.15 // indirect
+	github.com/tklauser/numcpus v0.10.0 // indirect
+	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
+	github.com/ugorji/go/codec v1.3.0 // indirect
+	github.com/yusufpapurcu/wmi v1.2.4 // indirect
+	go.etcd.io/etcd/api/v3 v3.6.5 // indirect
+	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
+	go.opentelemetry.io/otel v1.37.0 // indirect
+	go.opentelemetry.io/otel/metric v1.37.0 // indirect
+	go.opentelemetry.io/otel/trace v1.37.0 // indirect
+	go.uber.org/mock v0.5.0 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	go.uber.org/zap v1.27.0 // indirect
+	golang.org/x/arch v0.20.0 // indirect
+	golang.org/x/crypto v0.40.0 // indirect
+	golang.org/x/mod v0.26.0 // indirect
+	golang.org/x/net v0.42.0 // indirect
+	golang.org/x/sync v0.16.0 // indirect
+	golang.org/x/sys v0.35.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
+	golang.org/x/tools v0.35.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250818200422-3122310a409c // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250818200422-3122310a409c // indirect
+	google.golang.org/protobuf v1.36.9 // indirect
+)