Enhance Docker support and configuration

- Updated .env.example to recommend using docker.env and secrets for sensitive data.
- Modified .gitignore to include docker.env and secrets directory.
- Adjusted docker-compose.yml to utilize environment files and updated port mappings.
- Implemented read_env_or_file utility for better environment variable management.
- Refactored portfolio and trades routers to use the new utility for fetching environment variables.
- Added integration and phase 2 test updates for new environment variable handling.
- Created new documentation for Docker operations and secret management.
- Added placeholder files for Docker secrets and configuration.

routers/trades.py

@@ -8,6 +8,7 @@ from fastapi.responses import HTMLResponse
 from fastapi.templating import Jinja2Templates
 from ib_async import LimitOrder, MarketOrder, Stock
 
+from config_utils import read_env_or_file
 import dependencies
 from risk_manager import RiskManager
 
@@ -15,7 +16,10 @@ router = APIRouter()
 templates = Jinja2Templates(directory="templates")
 logger = logging.getLogger(__name__)
 
-WEBHOOK_SECRET = os.getenv("WEBHOOK_SECRET", "your_super_secret_string_123")
+WEBHOOK_SECRET = (
+    read_env_or_file("WEBHOOK_SECRET", "your_super_secret_string_123")
+    or "your_super_secret_string_123"
+)
 risk = RiskManager()