fixed screenshot capture and conversion

tool/playwright.py

@@ -274,6 +274,8 @@ class PlaywrightTool:
         viewport_height: Optional[int] = None,
         ignore_https_errors: Optional[bool] = None,
         accept_downloads: bool = False,
+        emulate_viewport: bool = True,
+        start_maximized: bool = False,
     ) -> Iterator[Any]:
         """Context manager yielding a Playwright page with sane defaults."""
         self.require()
@@ -314,19 +316,26 @@ class PlaywrightTool:
             if browser_type is None:
                 browser_type = pw.chromium
 
+            launch_args = ["--disable-blink-features=AutomationControlled"]
+            if bool(start_maximized) and not h:
+                launch_args.append("--start-maximized")
+
             browser = browser_type.launch(
                 headless=h,
-                args=["--disable-blink-features=AutomationControlled"],
+                args=launch_args,
             )
             context_kwargs: Dict[str,
                                  Any] = {
-                                     "viewport": {
-                                         "width": vw,
-                                         "height": vh
-                                     },
                                      "ignore_https_errors": ihe,
                                      "accept_downloads": bool(accept_downloads),
                                  }
+            if bool(emulate_viewport):
+                context_kwargs["viewport"] = {
+                    "width": vw,
+                    "height": vh,
+                }
+            else:
+                context_kwargs["no_viewport"] = True
             if ua_value is not None:
                 context_kwargs["user_agent"] = ua_value