修复Django应用启动时的导入错误

- 在knowledge/apps.py的ready()方法中注册Celery任务
- 移除ops/__init__.py中的直接导入，避免循环依赖
- 简化tasks/__init__.py，使用延迟导入
- 解决"Apps aren't loaded yet"错误

🤖 Generated with [Claude Code](https://claude.ai/code)

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

apps/knowledge/apps.py

@@ -4,3 +4,36 @@ from django.apps import AppConfig
 class KnowledgeConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'knowledge'
+    
+    def ready(self):
+        """在Django应用准备好后注册Celery任务"""
+        try:
+            # 导入Celery应用
+            from ops import celery_app
+            
+            # 注册高级学习任务
+            try:
+                from knowledge.tasks.advanced_learning import (
+                    advanced_learning_by_document,
+                    batch_advanced_learning
+                )
+                celery_app.register_task(advanced_learning_by_document)
+                celery_app.register_task(batch_advanced_learning)
+                print("✅ Advanced learning tasks registered via app config")
+            except ImportError as e:
+                print(f"❌ Failed to register advanced learning tasks: {e}")
+            
+            # 注册媒体学习任务
+            try:
+                from knowledge.tasks.media_learning import (
+                    media_learning_by_document,
+                    media_learning_batch
+                )
+                celery_app.register_task(media_learning_by_document)
+                celery_app.register_task(media_learning_batch)
+                print("✅ Media learning tasks registered via app config")
+            except ImportError as e:
+                print(f"❌ Failed to register media learning tasks: {e}")
+                
+        except Exception as e:
+            print(f"⚠️  Failed to register tasks via app config: {e}")

apps/knowledge/tasks/__init__.py

@@ -1,6 +1,5 @@
 # coding=utf-8
 
 # Import tasks for Celery discovery
-# Note: We import the specific tasks, not * to avoid circular imports
-from .advanced_learning import advanced_learning_by_document, batch_advanced_learning
-from .media_learning import media_learning_by_document, media_learning_batch
+# Note: We use lazy imports to avoid Django app loading issues
+# Tasks will be imported when needed by Celery's autodiscover

apps/ops/__init__.py

@@ -8,26 +8,5 @@
 """
 from .celery import app as celery_app
 
-# Import and register advanced learning tasks
-try:
-    from knowledge.tasks.advanced_learning import (
-        advanced_learning_by_document,
-        batch_advanced_learning
-    )
-    # Register tasks with the celery app
-    celery_app.register_task(advanced_learning_by_document)
-    celery_app.register_task(batch_advanced_learning)
-except ImportError:
-    pass
-
-# Import and register media learning tasks
-try:
-    from knowledge.tasks.media_learning import (
-        media_learning_by_document,
-        media_learning_batch
-    )
-    # Register tasks with the celery app
-    celery_app.register_task(media_learning_by_document)
-    celery_app.register_task(media_learning_batch)
-except ImportError:
-    pass
+# 任务注册现在通过knowledge/apps.py的ready()方法处理
+# 这样可以避免Django应用未准备好时的导入问题