Input Sanitization

How shell metacharacter injection happens in Node.js SSH provisioning and how to fix it

A critical command injection vulnerability was discovered in `services/onuProvisionService.js`, where the `sanitizeCliInput` function only stripped newlines and carriage returns from user input before passing it to SSH shell streams. Attackers could inject shell metacharacters like semicolons, pipes, and backticks to execute arbitrary commands on network infrastructure devices such as ONU/ONT hardware. The fix expands the sanitization regex to strip all dangerous shell metacharacters, closing th