fix: update database environment variables in Dockerfile

- Add explicit database configuration variables
- Match environment variables with docker-compose.yaml
- Ensure consistency between services

Dockerfile

@@ -195,12 +195,19 @@ ENV FLASK_APP=app.py \
     PYTHONPATH=/app/api \
     PATH="/usr/local/bin:${PATH}" \
     STORAGE_DIR=/storage \
-    POSTGRES_HOST=db \
-    POSTGRES_PORT=5432 \
-    POSTGRES_DB=dify \
-    REDIS_HOST=redis \
-    REDIS_PORT=6379 \
-    REDIS_DB=0
+    # Database configuration
+    DB_USERNAME=${DB_USERNAME:-postgres} \
+    DB_PASSWORD=${DB_PASSWORD:-difyai123456} \
+    DB_HOST=${DB_HOST:-db} \
+    DB_PORT=${DB_PORT:-5432} \
+    DB_DATABASE=${DB_DATABASE:-dify} \
+    SQLALCHEMY_POOL_SIZE=${SQLALCHEMY_POOL_SIZE:-30} \
+    SQLALCHEMY_POOL_RECYCLE=${SQLALCHEMY_POOL_RECYCLE:-3600} \
+    # Redis configuration
+    REDIS_HOST=${REDIS_HOST:-redis} \
+    REDIS_PORT=${REDIS_PORT:-6379} \
+    REDIS_PASSWORD=${REDIS_PASSWORD:-difyai123456} \
+    REDIS_DB=${REDIS_DB:-0}
 
 # Copy entrypoint script
 COPY docker/entrypoint.sh /app/entrypoint.sh