[collector admin] massively improve usability of the TeileAdmin

collector/admin.py

@@ -2,4 +2,14 @@ from django.contrib import admin
 
 from .models import Teil
 
-admin.site.register(Teil)
+class TeileAdmin(admin.ModelAdmin):
+    list_display = ["name", "modified"]
+    list_filter = ["modified"]
+    search_fields = ["name"]
+    readonly_fields = ["modified"]
+    fieldsets = [
+        (None, {"fields": ["name"]}),
+        ("Read-Only", {"fields": ["modified"]}),
+    ]
+
+admin.site.register(Teil, TeileAdmin)