feat(etl): 初始化 etl_to_crawler 模块，验证三端连接

- 创建 etl_to_crawler/__init__.py, config.py, connections.py
- 使用 pg8000 替代 psycopg2-binary（macOS 二进制兼容问题）
- 验证 hikoon-data / hikoon-data-spider / new_music_library / crawler_dev / OSS 全部 OK
- 更新 requirements.txt

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

+import os
+from dotenv import load_dotenv
+
+load_dotenv()
+
+SOURCE_DB = {
+    'host': os.environ['SOURCE_DB_HOST'],
+    'port': int(os.environ['SOURCE_DB_PORT']),
+    'user': os.environ['SOURCE_DB_USER'],
+    'password': os.environ['SOURCE_DB_PASSWORD'],
+    'database': os.environ['SOURCE_DB_NAME'],
+    'charset': 'utf8mb4',
+}
+
+HK_SONGS_DB = {
+    'host': os.environ['TARGET_DB_HOST'],
+    'port': int(os.environ['TARGET_DB_PORT']),
+    'user': os.environ['TARGET_DB_USER'],
+    'password': os.environ['TARGET_DB_PASSWORD'],
+    'database': os.environ['TARGET_DB_NAME'],
+    'charset': 'utf8mb4',
+}
+
+CRAWLER_DB = {
+    'host': os.environ['CRAWLER_DB_HOST'],
+    'port': int(os.environ.get('CRAWLER_DB_PORT', '5432')),
+    'user': os.environ['CRAWLER_DB_USER'],
+    'password': os.environ['CRAWLER_DB_PASSWORD'],
+    'database': os.environ['CRAWLER_DB_NAME'],
+    'ssl_context': None,
+}
+
+OSS_CONFIG = {
+    'access_key_id': os.environ['OSS_ACCESS_KEY_ID'],
+    'access_key_secret': os.environ['OSS_ACCESS_KEY_SECRET'],
+    'endpoint': os.environ['OSS_ENDPOINT'],
+    'bucket_name': os.environ['OSS_BUCKET_NAME'],
+    'base_url': f"https://{os.environ['OSS_BUCKET_NAME']}.{os.environ['OSS_ENDPOINT']}",
+}
+
+PLATFORM_QQ = '1'
+PLATFORM_KUGOU = '2'
+PLATFORM_NETEASE = '4'
+PLATFORMS = [PLATFORM_QQ, PLATFORM_KUGOU, PLATFORM_NETEASE]
+
+BATCH_SIZE = 500

+import pymysql
+import pymysql.cursors
+import pg8000
+import oss2
+from .config import SOURCE_DB, HK_SONGS_DB, CRAWLER_DB, OSS_CONFIG
+
+
+def get_source_conn() -> pymysql.Connection:
+    return pymysql.connect(**SOURCE_DB, cursorclass=pymysql.cursors.DictCursor)
+
+
+def get_spider_conn() -> pymysql.Connection:
+    cfg = SOURCE_DB.copy()
+    cfg['database'] = 'hikoon-data-spider'
+    return pymysql.connect(**cfg, cursorclass=pymysql.cursors.DictCursor)
+
+
+def get_hk_songs_conn() -> pymysql.Connection:
+    return pymysql.connect(**HK_SONGS_DB, cursorclass=pymysql.cursors.DictCursor)
+
+
+def get_pg_conn() -> pg8000.Connection:
+    return pg8000.connect(**CRAWLER_DB)
+
+
+def get_oss_bucket() -> oss2.Bucket:
+    auth = oss2.Auth(OSS_CONFIG['access_key_id'], OSS_CONFIG['access_key_secret'])
+    return oss2.Bucket(auth, OSS_CONFIG['endpoint'], OSS_CONFIG['bucket_name'])

-pymysql
-python-dotenv
-oss2
-requests
-tqdm
-opencc-python-reimplemented
-pytest
+aliyun-python-sdk-core==2.16.0
+aliyun-python-sdk-kms==2.16.5
+asn1crypto==1.5.1
+certifi==2026.6.17
+cffi==2.0.0
+charset-normalizer==3.4.7
+cos_python_sdk_v5==1.9.44
+crcmod==1.7
+cryptography==49.0.0
+et_xmlfile==2.0.0
+exceptiongroup==1.3.1
+idna==3.18
+iniconfig==2.3.0
+jmespath==0.10.0
+OpenCC==1.4.0
+opencc-python-reimplemented==0.1.7
+openpyxl==3.1.5
+oss2==2.19.1
+packaging==26.2
+pg8000==1.31.5
+pluggy==1.6.0
+psycopg2==2.9.12
+pycparser==3.0
+pycryptodome==3.23.0
+Pygments==2.20.0
+PyMySQL==1.2.0
+pytest==9.1.1
+python-dateutil==2.9.0.post0
+python-dotenv==1.2.2
+requests==2.34.2
+scramp==1.4.12
+six==1.17.0
+tomli==2.4.1
+tqdm==4.68.3
+typing_extensions==4.15.0
+urllib3==2.7.0
+xmltodict==1.0.4