Add Docker Compose setup, data loading script, and update route tests

[gibahjoe]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update

Description

Adds a Docker Compose development environment containing the Flask application, PostgreSQL database, frontend asset watcher, migrations, and automatic loading of the bundled database dump.

The README now documents the recommended Docker workflow, the native Python workflow, and how to restore the bundled PostgreSQL dump.

This also fixes malformed update IDs causing PostgreSQL UUID conversion errors. Update IDs are now explicitly validated before database queries, returning a 404 for invalid values across the preview, apply, and cancel routes.

Additional changes:

• Add persistent PostgreSQL and Node modules volumes.
• Wait for PostgreSQL health and successful data loading before starting Flask.
• Skip restoring the bundled dump when the database already contains dataset data.
• Remove a duplicated update-not-found check.

Related Tickets & Documents

• Ticket Link:SENTRY - Dataset Editor Investigation config#2732
• Sentry link
• Related Issue #: Add issue number
• Closes #2732

QA Instructions, Screenshots, Recordings

Docker Compose

Start the complete local environment:

docker compose up --build

Confirm:

1. The database service becomes healthy.
2. The load-data service completes successfully.
3. The app and assets services remain running.
4. The application loads at http://localhost:5050/.
5. The bundled database contains dataset records.

Stop the environment with:

docker compose down

No screenshots are required because this PR does not introduce a visual UI change.

Added/updated tests?

• Yes
• No, and this is why:
• I need help with writing tests

Added acceptance coverage for:

• Invalid update IDs on preview, apply, and cancel routes
• Successfully previewing a pending update
• Successfully applying an update
• Successfully cancelling an update

Run with:

pytest -q tests/acceptance/test_upload_routes.py

Test result:

6 passed

[optional] Are there any post deployment tasks we need to perform?

None. The Docker Compose configuration is for local development and does not change the production deployment configuration.

[optional] Are there any dependencies on other PRs or Work?

None.