Fix missing imports in skills package to resolve integration test failures

Author: James Zhu

code_assistant_manager/skills/__init__.py

@@ -18,6 +18,8 @@
 from .droid import DroidSkillHandler
 from .gemini import GeminiSkillHandler
 from .qwen import QwenSkillHandler
+from .models import Skill, SkillRepo
+from .manager import SkillManager, VALID_APP_TYPES
 
 __all__ = [
     "Skill",
@@ -31,4 +33,5 @@
     "DroidSkillHandler",
     "CodebuddySkillHandler",
     "QwenSkillHandler",
+    "VALID_APP_TYPES",
 ]