You build with Claude Code or Cursor, the result works, you make one more change, suddenly the app is broken. Login no longer works, a file is empty, something in the database structure is different. Editor undo? Only works for one file. The AI touched eight. Anyone who has lived through this knows what comes next: three to four hours of repair. Anyone who has not lived through it will. There is a simple protection against it. It is free, proven for twenty years, and it is called Git. The number that explains everything 94 percent of professional developers use Git. That is the Stack Overflow Developer Survey 2024. Not "many", not "most", but almost all. In no other tool category is adoption that high. The reason is simple. Git makes mistakes repairable. You can jump back to any earlier state in a second, without losing anything. You can experiment without touching the running version. You have a complete history of who changed what when. If 94 percent of professionals use a tool, there is a reason.…