Fix: Expose endpoint with version/hash

[gabrnavarro]

What changed

Added a new GET /api/v2/meta endpoint that returns metadata about the currently deployed version of the API:

{
  "deploy_date": "2024-01-15T12:34:56+00:00",
  "hash": "abc123def456...",
  "tag": "2.7.0"
}

• deploy_date: ISO 8601 timestamp of the latest git commit (null if unavailable)
• hash: Full git commit hash (null if unavailable)
• tag: Git tag pointing at HEAD, if any (null if not tagged or unavailable)

Why

Exposes version/hash information useful for cache invalidation — clients can check the hash field to determine whether to flush their cache after a new deploy.

Fixes #1432

Testing

• Added test_meta_api to pokemon_v2/tests.py verifying the endpoint returns HTTP 200 with the expected deploy_date, hash, and tag fields.
• Ran existing tests (test_gender_api, test_language_api, test_meta_api) — all pass.

[Naramsim]

Hi! Thanks for the quick implementation! I'd like to discuss here even with other people the exposed properties.

Do @jemarq04 @PraaneshSelvaraj have any opinions on this?

[phalt]

Does this get translated through Ditto to the production environment?

[Naramsim]

Yes, it would be an endpoint listed here: https://pokeapi.co/api/v2/

[phalt]

These tests will always pass, because it is looking for the key, which is always there.

[jemarq04]

Yes, it would be an endpoint listed here: https://pokeapi.co/api/v2/

I think this would be great to provide in the API! I did a local test build and I don't actually see the 'meta' endpoint at the local version of https://pokeapi.co/api/v2/. Is this expected with how Ditto works? I'm not familiar with how this tool is used in the framework. Navigating to /api/v2/meta does provide the expected response.

[Naramsim]

I expected it to be listed on the root endpoint. We need it to be listed there for Ditto

Probably a change is needed for pokemon_v2/urls.py