Finished! (Took me 3 days)
Private use characters are encoded in Variation Selectors and Latin Ext. D.
A work-in-progress (with rudimentary attempts at including common non-arabic punctuation), best viewed at large sizes. I tried to fill up every Arabic glyph slot, but some characters are unfamiliar to me as a native Arabic speaker, so if you happen notice an inaccuracy please notify me so I can correct it! Also, the riyal symbol looks weird because I attempted to make it look somewhat similar to رس in addition to the full word... it kind of works if you squint at it haha.
Unfortunately this font will remain incomplete indefinitely thanks to FontStruct's rather frustrating omissions/quirks (no أ/إ/ؤ/ئ, no connected urdu & farsi characters, glyph for isolated baa' is erroneously displayed when medial form is typed, etc.) but it was good practice at the very least!This is a clone