docs: document deviceScaleFactor and IPv6 embedded-IPv4 filtering

Add the deviceScaleFactor screenshot form field and note that IsPublicIP unwraps IPv4-mapped, 6to4, and Teredo addresses.

Author: gulien

docs/convert-with-chromium/_shared/_rendering_behavior/_rendering_behavior_screenshot.mdx

@@ -25,6 +25,13 @@ import WaitFor from "./_wait_for.mdx";
       description:
         "Define whether to clip the screenshot according to the device dimensions.",
     },
+    {
+      name: "deviceScaleFactor",
+      type: "number",
+      defaultValue: "1",
+      description:
+        "The device scale ratio, controlling the screenshot pixel density. Set to '2' for retina-quality output.",
+    },
     {
       name: "format",
       type: "enum",
@@ -71,6 +78,7 @@ ${props.curlOutput}
 **The viewport defines the image.** Unlike PDFs which paginate content, screenshots capture the browser's viewport exactly as rendered.
 
 - **Resolution:** Ensure you set the `width` and `height` form fields to match your desired target device (e.g., `1920`x`1080` for desktop, `375`x`812` for mobile).
+- **Pixel density:** Raise `deviceScaleFactor` for high-DPI output. A value of `2` doubles the captured pixels, matching a retina display.
 - If your screenshot's content is repeated and clipped, consider setting the `skipNetworkIdleEvent` form field to false (see issue [#1065](https://github.com/gotenberg/gotenberg/issues/1065#issuecomment-2670882337)).
 
 :::tip

docs/outbound-url-filtering.mdx

@@ -51,7 +51,7 @@ Each module exposes the same two boolean variables. All default to `false`.
 | `LIBREOFFICE_DENY_PRIVATE_IPS`       | Rejects LibreOffice outbound fetches resolving to a non-public IP.           |
 | `LIBREOFFICE_DENY_PUBLIC_IPS`        | Rejects LibreOffice outbound fetches resolving to a public IP.               |
 
-Non-public means loopback, RFC1918, link-local, or IPv6 unique-local.
+Non-public means loopback, RFC1918, link-local, or IPv6 unique-local. The check also unwraps IPv6 forms that embed an IPv4 destination, IPv4-mapped (`::ffff:10.0.0.1`), IPv4-translated, 6to4 (`2002::/16`), and Teredo (`2001::/32`), and rejects them when the embedded IPv4 is non-public.
 
 LibreOffice also exposes `LIBREOFFICE_ALLOW_LIST` and `LIBREOFFICE_DENY_LIST`, mirroring Chromium and webhook.