refactor(crawling): improve type hints and code cleanup

- Added proper return type hints for DeepCrawlStrategy.arun method
- Added __call__ method to DeepCrawlStrategy for easier usage
- Removed redundant comments and imports
- Cleaned up type hints in DFS strategy
- Removed empty docker_client.py and .continuerules
- Added .private/ to gitignore

BREAKING CHANGE: DeepCrawlStrategy.arun now returns Union[CrawlResultT, List[CrawlResultT], AsyncGenerator[CrawlResultT, None]]

.gitignore

@@ -250,4 +250,5 @@ continue_config.json
 
 .prompts/
 
-.llm.env
+.llm.env
+.private/