fix: clean up requirements and import command, update README

- requirements.txt: remove unused packages (django-imagekit, django-taggit, python-slugify), keep 4 actual deps
- import_example_images.py: remove grid_size variable and param to fix TypeError
- README.md: correct repo dir name, add comment/search/category/login docs, fix tech stack and project structure, update data model (remove grid_size, add Comment), add v1.1.0 changelog

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

gallery/management/commands/import_example_images.py

@@ -120,16 +120,11 @@ class Command(BaseCommand):
         # 随机选择分类
         category = random.choice(categories) if categories else None
 
-        # 根据图片比例智能选择网格尺寸
-        # 这里先使用默认值，图片保存时会根据实际尺寸调整
-        grid_size = 'medium'
-
         # 创建作品
         artwork = Artwork(
             title=titles[title_index],
             description=descriptions[description_index],
             order=index * 10,  # 按导入顺序排序
-            grid_size=grid_size,
             category=category
         )