refactor(proxy): consolidate proxy configuration handling

Moves ProxyConfig from configs/ directory into proxy_strategy.py to improve code organization and reduce fragmentation. Updates all imports and type hints to reflect the new location.

Key changes:
- Moved ProxyConfig class from configs/proxy_config.py to proxy_strategy.py
- Updated type hints in async_configs.py to support ProxyConfig
- Fixed proxy configuration handling in browser_manager.py
- Updated documentation and examples to use new import path

BREAKING CHANGE: ProxyConfig import path has changed from crawl4ai.configs to crawl4ai.proxy_strategy

crawl4ai/async_crawler_strategy.py

@@ -767,6 +767,7 @@ class AsyncPlaywrightCrawlerStrategy(AsyncCrawlerStrategy):
             # Handle wait_for condition
             # Todo: Decide how to handle this
             if not config.wait_for and config.css_selector and False:
+            # if not config.wait_for and config.css_selector:
                 config.wait_for = f"css:{config.css_selector}"
 
             if config.wait_for:
@@ -806,8 +807,28 @@ class AsyncPlaywrightCrawlerStrategy(AsyncCrawlerStrategy):
             if config.remove_overlay_elements:
                 await self.remove_overlay_elements(page)
 
-            # Get final HTML content
-            html = await page.content()
+            if config.css_selector:
+                try:
+                    # Handle comma-separated selectors by splitting them
+                    selectors = [s.strip() for s in config.css_selector.split(',')]
+                    html_parts = []
+                    
+                    for selector in selectors:
+                        try:
+                            content = await page.evaluate(f"document.querySelector('{selector}')?.outerHTML || ''")
+                            html_parts.append(content)
+                        except Error as e:
+                            print(f"Warning: Could not get content for selector '{selector}': {str(e)}")
+                    
+                    # Wrap in a div to create a valid HTML structure
+                    html = f"<div class='crawl4ai-result'>\n" + "\n".join(html_parts) + "\n</div>"                    
+                except Error as e:
+                    raise RuntimeError(f"Failed to extract HTML content: {str(e)}")
+            else:
+                html = await page.content()
+            
+            # # Get final HTML content
+            # html = await page.content()
             await self.execute_hook(
                 "before_return_html", page=page, html=html, context=context, config=config
             )