docs(examples): update proxy rotation demo and disable other demos

Modify proxy rotation example to include empty user agent setting and comment out other demo functions for focused testing. This change simplifies the demo file to focus specifically on proxy rotation functionality.

No breaking changes.

docs/examples/v0_4_3b2_features_demo.py

@@ -297,8 +297,7 @@ async def demo_proxy_rotation():
             }
         except Exception as e:
             print(f"Error loading proxy: {e}")
-            return None
-    
+            return None    
     
     # Create 10 test requests to httpbin
     urls = ["https://httpbin.org/ip"] * 2
@@ -314,7 +313,7 @@ async def demo_proxy_rotation():
                 continue
                 
             # Create new config with proxy
-            current_config = run_config.clone(proxy_config=proxy)
+            current_config = run_config.clone(proxy_config=proxy, user_agent="")
             result = await crawler.arun(url=url, config=current_config)
             
             if result.success:
@@ -334,18 +333,18 @@ async def main():
     
     # Efficiency & Speed Demos
     print("\n🚀 EFFICIENCY & SPEED DEMOS")
-    await demo_memory_dispatcher()
-    await demo_streaming_support()
-    await demo_content_scraping()
+    # await demo_memory_dispatcher()
+    # await demo_streaming_support()
+    # await demo_content_scraping()
     
     # # LLM Integration Demos
     print("\n🤖 LLM INTEGRATION DEMOS")
-    await demo_json_schema_generation()
-    await demo_llm_markdown()
+    # await demo_json_schema_generation()
+    # await demo_llm_markdown()
     
     # # Core Improvements
     print("\n🔧 CORE IMPROVEMENT DEMOS")
-    await demo_robots_compliance()
+    # await demo_robots_compliance()
     await demo_proxy_rotation()
 
 if __name__ == "__main__":