chore: Update sensitive information in documentation and code to use environment variables

This commit replaces hardcoded sensitive information, such as database passwords and secret keys, in the README and deployment documentation with placeholders and instructions to use environment variables. This change enhances security by preventing exposure of sensitive data in the codebase. Additionally, it updates the database session management to raise an error if the DATABASE_URL environment variable is not set, ensuring proper configuration for development environments.

README.md

@@ -123,20 +123,20 @@ For development, you can use the shared development PostgreSQL server:
 - **Host**: 10.0.10.181
 - **Port**: 5432
 - **User**: ladmin
-- **Password**: C0caC0la
+- **Password**: [Contact administrator for password]
 
 **Development Server:**
 - **Host**: 10.0.10.121
 - **User**: appuser
-- **Password**: C0caC0la
+- **Password**: [Contact administrator for password]
 
 Configure your `.env` file for development:
 ```bash
 # Main database (dev)
-DATABASE_URL=postgresql+psycopg2://ladmin:C0caC0la@10.0.10.181:5432/punimtag
+DATABASE_URL=postgresql+psycopg2://ladmin:[PASSWORD]@10.0.10.181:5432/punimtag
 
 # Auth database (dev)
-DATABASE_URL_AUTH=postgresql+psycopg2://ladmin:C0caC0la@10.0.10.181:5432/punimtag_auth
+DATABASE_URL_AUTH=postgresql+psycopg2://ladmin:[PASSWORD]@10.0.10.181:5432/punimtag_auth
 ```
 
 **Install PostgreSQL (if not installed):**
@@ -201,10 +201,10 @@ DATABASE_URL_AUTH=postgresql+psycopg2://punimtag:punimtag_password@localhost:543
 **Development Server:**
 ```bash
 # Main database (dev PostgreSQL server)
-DATABASE_URL=postgresql+psycopg2://ladmin:C0caC0la@10.0.10.181:5432/punimtag
+DATABASE_URL=postgresql+psycopg2://ladmin:[PASSWORD]@10.0.10.181:5432/punimtag
 
 # Auth database (dev PostgreSQL server)
-DATABASE_URL_AUTH=postgresql+psycopg2://ladmin:C0caC0la@10.0.10.181:5432/punimtag_auth
+DATABASE_URL_AUTH=postgresql+psycopg2://ladmin:[PASSWORD]@10.0.10.181:5432/punimtag_auth
 ```
 
 **Automatic Initialization:**
@@ -250,7 +250,7 @@ The separate auth database (`punimtag_auth`) stores frontend website user accoun
   # On macOS with Homebrew:
   brew install redis
   brew services start redis
-  
+  1
   # Verify Redis is running:
   redis-cli ping  # Should respond with "PONG"
   ```
@@ -819,13 +819,13 @@ The project includes scripts for deploying to the development server.
 **Development Server:**
 - **Host**: 10.0.10.121
 - **User**: appuser
-- **Password**: C0caC0la
+- **Password**: [Contact administrator for password]
 
 **Development Database:**
 - **Host**: 10.0.10.181
 - **Port**: 5432
 - **User**: ladmin
-- **Password**: C0caC0la
+- **Password**: [Contact administrator for password]
 
 #### Build and Deploy to Dev