Transparent background

The problem (see research 13 + 04)

Almost every modern T2I VAE is RGB-only. Asking Imagen 3/4 or Gemini 2.5/3 Flash Image for a "transparent logo" triggers one of two failures:

1. Flat background — DALL·E 3, Stable Diffusion families render a white/gray background that must be matted.
2. Checkerboard as RGB pixels — Gemini/Imagen literally render the gray-and-white 8×8 tile pattern (because Photoshop screenshots in their training data show transparency that way). This is the "weird boxes" users report. It cannot be fixed by prompting.

Fix hierarchy (apply first that fits)

1. Route to a native-RGBA provider