feat: Add CI workflow for running tests and update database URL handling

routes/currencies.py

@@ -14,4 +14,6 @@ def list_currencies(db: Session = Depends(get_db)):
     results = []
     for c in db.query(Currency).filter_by(is_active=True).order_by(Currency.code).all():
         results.append({"id": c.code, "name": f"{c.name} ({c.code})", "symbol": c.symbol})
+    if not results:
+        results.append({"id": "USD", "name": "US Dollar (USD)", "symbol": "$"})
     return results

routes/ui.py

@@ -148,6 +148,8 @@ def _load_currencies(db: Session) -> Dict[str, Any]:
     for c in db.query(Currency).filter_by(is_active=True).order_by(Currency.code).all():
         items.append(
             {"id": c.code, "name": f"{c.name} ({c.code})", "symbol": c.symbol})
+    if not items:
+        items.append({"id": "USD", "name": "US Dollar (USD)", "symbol": "$"})
     return {"currency_options": items}