feat(browser): implement modular browser management system

Adds a new browser management system with strategy pattern implementation:
- Introduces BrowserManager class with strategy pattern support
- Adds PlaywrightBrowserStrategy, CDPBrowserStrategy, and BuiltinBrowserStrategy
- Implements BrowserProfileManager for profile management
- Adds PagePoolConfig for browser page pooling
- Includes comprehensive test suite for all browser strategies

BREAKING CHANGE: Browser management has been moved to browser/ module. Direct usage of browser_manager.py and browser_profiler.py is deprecated.

docs/examples/hello_world.py

@@ -9,6 +9,26 @@ from crawl4ai import (
     CrawlResult
 )
 
+async def example_cdp():
+    browser_conf = BrowserConfig(
+        headless=False,
+        cdp_url="http://localhost:9223"
+    )
+    crawler_config = CrawlerRunConfig(
+        session_id="test",
+        js_code = """(() => { return {"result": "Hello World!"} })()""",
+        js_only=True
+    )
+    async with AsyncWebCrawler(
+        config=browser_conf,
+        verbose=True,
+    ) as crawler:
+        result : CrawlResult = await crawler.arun(
+            url="https://www.helloworld.org",
+            config=crawler_config,
+        )
+        print(result.js_execution_result)
+                   
 
 async def main():
     browser_config = BrowserConfig(headless=True, verbose=True)
@@ -16,18 +36,15 @@ async def main():
         crawler_config = CrawlerRunConfig(
             cache_mode=CacheMode.BYPASS,
             markdown_generator=DefaultMarkdownGenerator(
-                # content_filter=PruningContentFilter(
-                #     threshold=0.48, threshold_type="fixed", min_word_threshold=0
-                # )
+                content_filter=PruningContentFilter(
+                     threshold=0.48, threshold_type="fixed", min_word_threshold=0
+                )
             ),
         )
         result : CrawlResult = await crawler.arun(
-            # url="https://www.helloworld.org", config=crawler_config
-            url="https://www.kidocode.com", config=crawler_config
+            url="https://www.helloworld.org", config=crawler_config
         )
         print(result.markdown.raw_markdown[:500])
-        # print(result.model_dump())
-
 
 if __name__ == "__main__":
     asyncio.run(main())