That shed doesn't belong to you. I know you are the supervisor, and it is your job to take care of the stuff in the shed. But it's. not. yours.
Repeat this to yourself: "It's not mine. It's not mine. It's not mine."
Because you are seriously worked up over nothing. Nothing, I tell you!
They went into the shed to fix the problem you've been whining about for months! They moved the stuff in order to keep it dry and non-muddied. Really, they were trying to help you.
So, the bottom line is:
- No, you can't just lock the door at 3:45. And if you do, don't be surprised if someone uses another key to unlock it. That's what they do to open doors.
- Yes, you can talk to the construction manager, but he's going to tell you the same dang thing.
- Get over yourself, and get over it.