refactor: 引入 ScanSession，替代全局状态穿透扫描管道 (Phase 1-3)

- 新增 common/session.go: ScanSession 结构体封装 Config/State/Params/Dialer
- RunScan/Strategy/ExecuteScanTasks/executeScanTask 全部接收 session
- Plugin 接口从 Scan(ctx, info, config, state) 改为 Scan(ctx, info, session)
- 48 个插件实现统一更新签名
- Web API 构建 ScanSession 传给 RunScan
- CLI 模式通过 Initialize() 创建 session

plugins/services/postgresql.go

@@ -25,7 +25,9 @@ func NewPostgreSQLPlugin() *PostgreSQLPlugin {
 	}
 }
 
-func (p *PostgreSQLPlugin) Scan(ctx context.Context, info *common.HostInfo, config *common.Config, state *common.State) *ScanResult {
+func (p *PostgreSQLPlugin) Scan(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
+	config := session.Config
+	state := session.State
 	target := info.Target()
 
 	if config.DisableBrute {