Containerize and deploy Flask tutorial app with Docker

[gasalabi]

Containerizes the Flaskr tutorial app as part of the Omega Solutions DevOps internship assignment.

• Added Dockerfile (python:3.12-slim base, handles flit_core build requirement, initializes SQLite db on startup)
• Added deploy.sh to automate build/run with idempotent redeployment
• Documented build/run instructions and troubleshooting in README.md
• Added screenshots of the running app and container logs

[ThiefMaster]

as part of the Omega Solutions DevOps internship assignment

I have no idea who or what Omega Solutions is, but you need to tell your supervisor/lecturer/whatever that it is NOT acceptable to ask students/interns to randomly open PRs to other people's projects when it should be quite obvious that these PRs are not welcome in these projects.

If they want to teach students how to use GitHub that's fine, but then THEY should provide a repo to fork and make a contribution to.

We have received 5 of these PRs today, two from you (who seems to have realized they should not have been opened here since you closed them), and three from assuming someone else doing the same assignment.