Replace the previous "circle + shaft + curl" silhouette (which read
more like a magnifying glass) with a proper skeleton-key anatomy:
- BOW: round decorative loop with center hole (the part you hold)
- SHAFT: long horizontal rod (= the body of the key)
- BIT: notched tooth hanging down from the shaft end (the part
that engages the lock — the iconic key-tooth profile)
Same change in skeletonkey.c BANNER and README.md.
Bump 0.4.0 → 0.4.1.