Felt Orbit v39 - silhouette sampled from uploaded manta reference

Base: confirmed-stable v36.
The manta body contour is sampled directly from the uploaded reference image,
row by row, then mapped to the OLED. The largest connected near-black component
is used so watermark graphics do not determine the outer contour.

No new Pd objects or connections.
No gPixel, no overlay, no animation, no extra gFlip.
Only the 36 already-working gLine message coordinates were replaced.
Audio/control untouched.
Pd connection-index validation passed.
