feat: enhance crawler with overlay removal and improved screenshot capabilities

• Add smart overlay removal system for handling popups and modals
• Improve screenshot functionality with configurable timing controls
• Implement URL normalization and enhanced link processing
• Add custom base directory support for cache storage
• Refine external content filtering and social media domain handling

This commit significantly improves the crawler's ability to handle modern
websites by automatically removing intrusive overlays and providing better
screenshot capabilities. URL handling is now more robust with proper
normalization and duplicate detection. The cache system is more flexible
with customizable base directory support.

Breaking changes: None
Issue numbers: None

crawl4ai/async_webcrawler.py

@@ -23,13 +23,15 @@ class AsyncWebCrawler:
         self,
         crawler_strategy: Optional[AsyncCrawlerStrategy] = None,
         always_by_pass_cache: bool = False,
+        base_directory: str = str(Path.home()),
         **kwargs,
     ):
         self.crawler_strategy = crawler_strategy or AsyncPlaywrightCrawlerStrategy(
             **kwargs
         )
         self.always_by_pass_cache = always_by_pass_cache
-        self.crawl4ai_folder = os.path.join(Path.home(), ".crawl4ai")
+        # self.crawl4ai_folder = os.path.join(Path.home(), ".crawl4ai")
+        self.crawl4ai_folder = os.path.join(base_directory, ".crawl4ai")
         os.makedirs(self.crawl4ai_folder, exist_ok=True)
         os.makedirs(f"{self.crawl4ai_folder}/cache", exist_ok=True)
         self.ready = False