refactor(models): rename final_url to redirected_url for consistency

Renames the final_url field to redirected_url across all components to maintain
consistent terminology throughout the codebase. This change affects:
- AsyncCrawlResponse model
- AsyncPlaywrightCrawlerStrategy
- Documentation and examples

No functional changes, purely naming consistency improvement.

crawl4ai/models.py

@@ -132,7 +132,7 @@ class AsyncCrawlResponse(BaseModel):
     get_delayed_content: Optional[Callable[[Optional[float]], Awaitable[str]]] = None
     downloaded_files: Optional[List[str]] = None
     ssl_certificate: Optional[SSLCertificate] = None
-    final_url: Optional[str] = None
+    redirected_url: Optional[str] = None
 
     class Config:
         arbitrary_types_allowed = True