Challenge 1: Register and Customize a Model — Possible Solution
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# catalog/admin.py

from django.contrib import admin
from .models import Tag

@admin.register(Tag)
class TagAdmin(admin.ModelAdmin):
    list_display = ["name"]
    search_fields = ["name"]

WHY THIS WORKS
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- @admin.register(Tag) is equivalent to writing
  admin.site.register(Tag, TagAdmin) separately — the decorator form ties
  the TagAdmin customization class to the Tag model in one step, right
  where the class is defined.
- list_display = ["name"] tells the admin's list view to show the name
  column explicitly — without this, Tag's list page would fall back to
  showing only Tag's __str__ representation for each row (which happens
  to also just be name here, but list_display makes the column
  explicit and extensible if more fields are added to Tag later).
- search_fields = ["name"] adds a search box above the list view that
  filters tags by a case-insensitive substring match on name — useful
  once a catalog has more than a handful of tags to scroll through.
- This mirrors the BookAdmin pattern from the chapter exactly, just
  applied to a simpler model with fewer fields worth surfacing.