Add prestart service for backend setup

[raphaelauv]

Add prestart service to compose.yml for backend initialization.

otherwise backend fail with

ERROR:  relation "user" does not exist at character 138

2026-09-29T16:14:27.394867476Z 2026-09-29 16:14:27.394 UTC [78] STATEMENT:  SELECT "user".email, "user".is_active, "user".is_superuser, "user".full_name, "user".id, "user".hashed_password, "user".created_at 

2026-09-29T16:14:27.394872616Z FROM "user" 

2026-09-29T16:14:27.394876012Z WHERE "user".email = $1::VARCHAR

[YuriiMotov]

Thanks for you interest!

The prestart service was intentionally removed recently. See #2426

Also, please, follow the rules of the repository.

We ask people to only open PRs when it's explicitly requested by maintainers.
See https://tiangolo.com/open-source/contributing/ and PR description template:

Please start with a GitHub Discussion.

Once a team member asks you to open a PR, create it and link the discussion here.

Thanks for understanding!

[raphaelauv]

Okay but this info is not present on the readme , would you accept a pr ?

[YuriiMotov]

Okay but this info is not present on the readme , would you accept a pr ?

I think it's described well:

full-stack-fastapi-template/backend/README.md

Lines 40 to 47 in e99fbae

	## Full Stack with Docker Compose
	To run the backend and built frontend in Docker Compose:
	```console
	$ docker compose run --rm backend bash scripts/prestart.sh
	$ docker compose watch
	```

full-stack-fastapi-template/frontend/README.md

Lines 94 to 101 in e99fbae

	## End-to-End Testing with Playwright
	The frontend includes initial end-to-end tests using Playwright. To run the tests, you need to have the Docker Compose stack running. Start the stack with the following command:
	```bash
	docker compose run --rm backend bash scripts/prestart.sh
	docker compose up -d --wait backend
	```

Am I missing anything?

[raphaelauv]

Yes , the user that want to discover and run this repo example by doing

git clone ...
cd ...
docker compose up -d

Will not understand why he can't log in, let's keep in mind that this repo is for beginners.

[YuriiMotov]

I believe if they face any issues they will go and read docs that clearly describe the commands they should use. Or, they will use AI that will quickly find the root cause.

If you still think we need to update docs or revert removing the prestart service, please start a discussion and let's gather community feedback

[raphaelauv]

you never teached