setup vite and integrate fully with django

- vite starts with `python manage.py runserver`
- add templatetags to simply load vite hmr and entry points
- add eslint (recheck rules)
- enable non-strict ts

src/pretix/base/management/commands/runserver.py

@@ -0,0 +1,38 @@
+# SPDX-FileCopyrightText: 2023-present Tobias Kunze
+# SPDX-License-Identifier: AGPL-3.0-only WITH LicenseRef-Pretalx-AGPL-3.0-Terms
+
+"""This command supersedes the Django-inbuilt runserver command.
+
+It runs the local frontend server, if node is installed and the setting
+is set.
+"""
+import os
+import atexit
+import subprocess
+from pathlib import Path
+
+from django.conf import settings
+from django.contrib.staticfiles.management.commands.runserver import Command as Parent
+from django.utils.autoreload import DJANGO_AUTORELOAD_ENV
+
+
+class Command(Parent):
+    def handle(self, *args, **options):
+        # Only start Vite in the non-main process of the autoreloader
+        if settings.VITE_DEV_MODE and os.environ.get(DJANGO_AUTORELOAD_ENV) != "true":
+            # Start the vite server in the background
+            vite_server = subprocess.Popen(
+                ["npm", "run", "dev"],
+                cwd=Path(__file__).parent.parent.parent.parent.parent
+            )
+
+            def cleanup():
+                vite_server.terminate()
+                try:
+                    vite_server.wait(timeout=5)
+                except subprocess.TimeoutExpired:
+                    vite_server.kill()
+            
+            atexit.register(cleanup)
+
+        super().handle(*args, **options)