refactor(proxy): move ProxyConfig to async_configs and improve LLM token handling

Moved ProxyConfig class from proxy_strategy.py to async_configs.py for better organization.
Improved LLM token handling with new PROVIDER_MODELS_PREFIXES.
Added test cases for deep crawling and proxy rotation.
Removed docker_config from BrowserConfig as it's handled separately.

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

docs/examples/quickstart_examples_set_1.py

@@ -4,7 +4,7 @@ import json
 import base64
 from pathlib import Path
 from typing import List
-from crawl4ai.proxy_strategy import ProxyConfig
+from crawl4ai import ProxyConfig
 
 from crawl4ai import AsyncWebCrawler, CrawlerRunConfig, CacheMode, CrawlResult
 from crawl4ai import RoundRobinProxyStrategy

docs/examples/tutorial_v0.5.py

@@ -13,7 +13,7 @@ from crawl4ai.deep_crawling import (
 )
 from crawl4ai.deep_crawling.scorers import KeywordRelevanceScorer
 from crawl4ai.async_crawler_strategy import AsyncHTTPCrawlerStrategy
-from crawl4ai.proxy_strategy import ProxyConfig
+from crawl4ai import ProxyConfig
 from crawl4ai import RoundRobinProxyStrategy
 from crawl4ai.content_filter_strategy import LLMContentFilter
 from crawl4ai import DefaultMarkdownGenerator

docs/md_v2/blog/releases/0.5.0.md

@@ -251,7 +251,7 @@ from crawl4ai import (
     RoundRobinProxyStrategy,
 )
 import asyncio
-from crawl4ai.proxy_strategy import ProxyConfig
+from crawl4ai import ProxyConfig
 async def main():
     # Load proxies and create rotation strategy
     proxies = ProxyConfig.from_env()