PostgreSQL 의존성 및 내부 유틸리티 추가:

- `github.com/lib/pq` PostgreSQL 드라이버 vendor 디렉토리에 추가.
- PostgreSQL 관련 내부 패키지(`pqsql`, `proto`, `pqtime`, `pgpass`, `pgservice`, `pqutil`) 구현:
  - SQL 어휘 처리, 프로토콜 상수 및 구조 정의, 시간 파서/포맷터(`Parse`, `Format`).
  - `.pgpass` 파일 및 `pg_service.conf` 관리 기능 추가.
  - 파일/사용자 권한 검증 및 플랫폼별 사용자 정보 조회 기능 포함.
- 데이터베이스 초기화 로직 추가 (`services/db.go`):
  - PostgreSQL 연결 설정 및 초기 스키마 생성.
- 자동매매 관련 DB 레포지토리(`services/autotrade_repo.go`) 구현:
  - 자동매매 규칙 및 포지션 관리 로직 추가 (`dbInsertRule`, `dbLoadRules` 등).

vendor/github.com/lib/pq/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2011-2013, 'pq' Contributors. Portions Copyright (c) 2011 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.