Always assert root cause before requesting a fix

When something is broken, Burak Yigit Kaya investigates and explicitly states the root cause before asking for a fix. They confirm what went wrong (e.g., 'ttyUSB0 is a regular file, not a char device', 'stty returns ioctl error', 'AVR was physically ON the whole time') then direct a specific solution. They specify the invariant that must hold (e.g., 'must always be a char device', 'prevent regular-file shadowing'). Accept the user's diagnosis as correct and focus on implementing the stated fix rather than re-investigating. Cross-session pattern: this has recurred across multiple sessions involving the AVR serial bridge.