Make rare species collection fully green

[kylexrich]

Summary

• add a semantic green color for the Rare Species Collection hero
• use the green treatment for both the hero background and its shadow
• keep existing theme aliases compatible

Validation

• git diff --check
• confirmed the referenced Atlas entity is canonical shop_home and matches observation eec3f543-17ac-4ef2-9b7c-4bb35faf7648
• reproduced on iPhone 17 Pro Max / iOS 26.5: the existing background is green while the prior shadow is blue/purple
• source-contract checks confirm both the hero fill and shadow use rareSpeciesCollectionGreen
• fresh Revyl remote build blocked after four retries by org build capacity (No build capacity is available for this org)

Exact-device visual check

Rare Species Collection banner shown green on iPhone 17 Pro Max running iOS 26.5

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