Wait for a Dependency with a Timeout

A container's start script must wait until the database writes its readiness file before the app starts.

Task

Create the executable script /home/student/bin/wait-for.sh FILE TIMEOUT that:

• exits 0 as soon as FILE exists and is not empty, printing ready
• checks at least twice a second
• if that has not happened after TIMEOUT seconds, prints timeout waiting for FILE (with the real path) to stderr and exits 1
• never waits much longer than TIMEOUT seconds