Simplify database setup by preconfiguring credentials and instructions

Adds preconfigured PostgreSQL credentials and setup instructions to .env and documentation.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 91318273-c764-4fd4-be04-bdc12c38af32
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/0715008c-7244-40f4-befc-26c014852236/6e755801-08e8-4492-805e-ac3610de5a2a.jpg

replit.md

@@ -203,12 +203,13 @@ Preferred communication style: Simple, everyday language.
 - ✅ Real-time monitoring of data retention status with visual indicators
 
 ### Docker Configuration (January 9, 2025)
-- ✅ Complete Docker setup with multi-stage build for production optimization
-- ✅ Docker Compose configuration with PostgreSQL and application services
-- ✅ Automated database initialization and migration scripts
+- ✅ Complete Docker setup optimized for external PostgreSQL database
+- ✅ Docker Compose configuration with RegisFlow application only
+- ✅ Automated database connection and migration scripts for external PostgreSQL
 - ✅ Health checks and proper container orchestration
 - ✅ Production-ready configuration with security best practices
-- ✅ Persistent volumes for database and backup data
-- ✅ Environment variable configuration with .env.example template
+- ✅ Persistent volumes for backup data
+- ✅ Environment variable configuration with preconfigured PostgreSQL credentials
 - ✅ Comprehensive Docker documentation with deployment instructions
-- ✅ Nginx configuration removed for simplified deployment (application accessible on port 5000)
+- ✅ Nginx configuration removed for simplified deployment (application accessible on port 5000)
+- ✅ Preconfigured PostgreSQL user (regisflow/RegisFlow2024!) - only IP change needed