feat: Add URL-specific crawler configurations for multi-URL crawling

Implement dynamic configuration selection based on URL patterns to optimize crawling for different content types. This feature enables users to apply different crawling strategies (PDF extraction, content filtering, JavaScript execution) based on URL matching patterns.

Key additions:
- Add url_matcher and match_mode parameters to CrawlerRunConfig
- Implement is_match() method supporting string patterns, functions, and mixed lists
- Add MatchMode enum for OR/AND logic when combining multiple matchers
- Update AsyncWebCrawler.arun_many() to accept List[CrawlerRunConfig]
- Add select_config() method to dispatchers for runtime config selection
- First matching config wins, with fallback to default

Pattern matching supports:
- Glob-style strings: *.pdf, */blog/*, *api*
- Lambda functions: lambda url: 'github.com' in url
- Mixed patterns with AND/OR logic for complex matching

This enables optimal per-URL configuration:
- PDFs: Use PDFContentScrapingStrategy without JavaScript
- Blogs: Apply content filtering to reduce noise
- APIs: Skip JavaScript, use JSON extraction
- Dynamic sites: Execute only necessary JavaScript

Breaking changes: None - fully backward compatible

crawl4ai/async_dispatcher.py

@@ -1,4 +1,4 @@
-from typing import Dict, Optional, List, Tuple
+from typing import Dict, Optional, List, Tuple, Union
 from .async_configs import CrawlerRunConfig
 from .models import (
     CrawlResult,
@@ -96,11 +96,37 @@ class BaseDispatcher(ABC):
         self.rate_limiter = rate_limiter
         self.monitor = monitor
 
+    def select_config(self, url: str, configs: Union[CrawlerRunConfig, List[CrawlerRunConfig]]) -> CrawlerRunConfig:
+        """Select the appropriate config for a given URL.
+        
+        Args:
+            url: The URL to match against
+            configs: Single config or list of configs to choose from
+            
+        Returns:
+            The matching config, or the first config if no match, or a default config if empty list
+        """
+        # Single config - return as is
+        if isinstance(configs, CrawlerRunConfig):
+            return configs
+        
+        # Empty list - return default config
+        if not configs:
+            return CrawlerRunConfig()
+        
+        # Find first matching config
+        for config in configs:
+            if config.is_match(url):
+                return config
+        
+        # No match found - return first config as fallback
+        return configs[0]
+
     @abstractmethod
     async def crawl_url(
         self,
         url: str,
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
         task_id: str,
         monitor: Optional[CrawlerMonitor] = None,
     ) -> CrawlerTaskResult:
@@ -111,7 +137,7 @@ class BaseDispatcher(ABC):
         self,
         urls: List[str],
         crawler: AsyncWebCrawler,  # noqa: F821
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
         monitor: Optional[CrawlerMonitor] = None,
     ) -> List[CrawlerTaskResult]:
         pass
@@ -200,7 +226,7 @@ class MemoryAdaptiveDispatcher(BaseDispatcher):
     async def crawl_url(
         self,
         url: str,
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
         task_id: str,
         retry_count: int = 0,
     ) -> CrawlerTaskResult:
@@ -208,6 +234,9 @@ class MemoryAdaptiveDispatcher(BaseDispatcher):
         error_message = ""
         memory_usage = peak_memory = 0.0
         
+        # Select appropriate config for this URL
+        selected_config = self.select_config(url, config)
+        
         # Get starting memory for accurate measurement
         process = psutil.Process()
         start_memory = process.memory_info().rss / (1024 * 1024)
@@ -257,8 +286,8 @@ class MemoryAdaptiveDispatcher(BaseDispatcher):
                     retry_count=retry_count + 1
                 )
             
-            # Execute the crawl
-            result = await self.crawler.arun(url, config=config, session_id=task_id)
+            # Execute the crawl with selected config
+            result = await self.crawler.arun(url, config=selected_config, session_id=task_id)
             
             # Measure memory usage
             end_memory = process.memory_info().rss / (1024 * 1024)
@@ -316,7 +345,7 @@ class MemoryAdaptiveDispatcher(BaseDispatcher):
         self,
         urls: List[str],
         crawler: AsyncWebCrawler,
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
     ) -> List[CrawlerTaskResult]:
         self.crawler = crawler
         
@@ -470,7 +499,7 @@ class MemoryAdaptiveDispatcher(BaseDispatcher):
         self,
         urls: List[str],
         crawler: AsyncWebCrawler,
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
     ) -> AsyncGenerator[CrawlerTaskResult, None]:
         self.crawler = crawler
         
@@ -572,7 +601,7 @@ class SemaphoreDispatcher(BaseDispatcher):
     async def crawl_url(
         self,
         url: str,
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
         task_id: str,
         semaphore: asyncio.Semaphore = None,
     ) -> CrawlerTaskResult:
@@ -580,6 +609,9 @@ class SemaphoreDispatcher(BaseDispatcher):
         error_message = ""
         memory_usage = peak_memory = 0.0
 
+        # Select appropriate config for this URL
+        selected_config = self.select_config(url, config)
+
         try:
             if self.monitor:
                 self.monitor.update_task(
@@ -592,7 +624,7 @@ class SemaphoreDispatcher(BaseDispatcher):
             async with semaphore:
                 process = psutil.Process()
                 start_memory = process.memory_info().rss / (1024 * 1024)
-                result = await self.crawler.arun(url, config=config, session_id=task_id)
+                result = await self.crawler.arun(url, config=selected_config, session_id=task_id)
                 end_memory = process.memory_info().rss / (1024 * 1024)
 
                 memory_usage = peak_memory = end_memory - start_memory
@@ -654,7 +686,7 @@ class SemaphoreDispatcher(BaseDispatcher):
         self,
         crawler: AsyncWebCrawler,  # noqa: F821
         urls: List[str],
-        config: CrawlerRunConfig,
+        config: Union[CrawlerRunConfig, List[CrawlerRunConfig]],
     ) -> List[CrawlerTaskResult]:
         self.crawler = crawler
         if self.monitor: