Add Persian/Arabic Script Support

**Is your feature request related to a problem? Please describe.**
Roboto Flex is an incredible variable font family, but it currently lacks native support for Perso-Arabic scripts, making it unusable for Persian and Arabic UI/UX designs that require dynamic typographic controls.

**Describe the solution you'd like**
Add Arabic/Persian character sets with matching variable axes support (such as Weight and Width), allowing seamless multilingual integration for Right-To-Left (RTL) interfaces alongside Latin.

**Additional context**
Persian/Arabic is used by hundreds of millions of users worldwide, and having Roboto Flex support this script would be a massive leap forward for open-source RTL web/mobile typography.

No source files, tests, or entry points are named. Start by locating the font source and build workflow for Roboto Flex, then determine how script glyphs and variable-axis support are added. Done means Persian and Arabic characters work with matching Weight and Width behavior in RTL use alongside Latin.

Written by the indexing model from the issue text.