update requirements

README.md

@@ -49,8 +49,11 @@ sudo ./install.sh
    sudo apt-get update
    sudo apt-get install python3 python3-pip python3-venv
 
-   # RHEL/CentOS/Fedora
-   sudo dnf install python3 python3-pip python3-venv
+   # RHEL/CentOS/Fedora (venv is built-in with Python 3.3+)
+   sudo dnf install python3 python3-pip
+
+   # Verify venv is available
+   python3 -m venv --help
    ```
 
 2. **Create service user**:

requirements.txt

@@ -1,4 +1,4 @@
-flask==2.3.3
-ntfy==2.7.0
-pyyaml==6.0.1
-gunicorn==21.2.0
+flask>=2.0,<3.0
+ntfy>=2.7.0
+pyyaml>=6.0
+gunicorn>=21.0