fix: unpin playwright to resolve crawl4ai dependency conflict

crawl4ai==0.4.247 requires playwright>=1.49.0 which conflicts with
the hard-pinned playwright==1.42.0. Loosen to playwright>=1.49.0.
pytest-playwright==0.4.4 accepts playwright>=1.18 so no conflict.

requirements.txt

@@ -53,7 +53,7 @@ pytest-mock==3.12.0
 behave==1.2.6
 httpx==0.25.1
 faker==22.0.0
-playwright==1.42.0
+playwright>=1.49.0
 pytest-playwright==0.4.4
 
 # --- Web Scraper (optional, feature-gated) ---