feat: add nginx reverse proxy and Let's Encrypt TLS setup

- Add nginx config for SSL termination and HTTP->HTTPS redirect
- Add init-letsencrypt.sh script for automated certificate provisioning
- Update docker-compose.yml: add nginx service, expose web on internal port only
- Fix Evotor OAuth token exchange: move client credentials to form body
- Add request logging for token exchange errors
- Update BASE_URL to https://evosync.ru and set default in docker-compose
- Add refresh_token field to EvotorConnection model

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

web/models.py

@@ -37,6 +37,8 @@ class EvotorConnection(Base):
     access_token = Column(Text, nullable=False)
     store_id = Column(String(255), nullable=True)
     store_name = Column(String(255), nullable=True)
+    refresh_token = Column(Text, nullable=True)
+    token_expires_at = Column(DateTime, nullable=True)
     is_online = Column(Boolean, default=False, server_default="0", nullable=False)
     last_checked_at = Column(DateTime, nullable=True)
     connected_at = Column(DateTime, server_default=func.now(), nullable=False)