✨(project) Django boilerplate

This commit introduces a boilerplate inspired by https://github.com/numerique-gouv/impress.
The code has been cleaned to remove unnecessary Impress logic and dependencies.

Changes made:
- Removed Minio, WebRTC, and create bucket from the stack.
- Removed the Next.js frontend (it will be replaced by Vite).
- Cleaned up impress-specific backend logics.

The whole stack remains functional:
- All tests pass.
- Linter checks pass.
- Agent Connexion sources are already set-up.

Why clear out the code?

To adhere to the KISS principle, we aim to maintain a minimalist codebase. Cloning Impress
allowed us to quickly inherit its code quality tools and deployment configurations for staging,
pre-production, and production environments.

What’s broken?
- The tsclient is not functional anymore.
- Some make commands need to be fixed.
- Helm sources are outdated.
- Naming across the project sources are inconsistent (impress, visio, etc.)
- CI is not configured properly.

This list might be incomplete. Let's grind it.

src/backend/core/urls.py

@@ -0,0 +1,24 @@
+"""URL configuration for the core app."""
+from django.conf import settings
+from django.urls import include, path
+
+from rest_framework.routers import DefaultRouter
+
+from core.api import viewsets
+from core.authentication.urls import urlpatterns as oidc_urls
+
+# - Main endpoints
+router = DefaultRouter()
+router.register("users", viewsets.UserViewSet, basename="users")
+
+urlpatterns = [
+    path(
+        f"api/{settings.API_VERSION}/",
+        include(
+            [
+                *router.urls,
+                *oidc_urls,
+            ]
+        ),
+    ),
+]