feat: bring onchain relics to practice parity

[CryptoMickle]

Summary

• award one random relic after each boss and let the player choose whether to equip it
• track duplicate relic drops with counters without stacking their effects
• make rare relics genuinely rare, with somewhat better odds after tier 4
• allow owned relics to be equipped or unequipped between rooms
• preserve earlier snapshots while adding the new relic and merchant progression

Verification

• all 130 contract tests passed
• both GitHub Foundry checks passed
• contract size build passed
• Delveworn remains below the EIP-170 runtime limit

RISE Testnet deployment

• chain ID: 11155931
• Delveworn: 0xf5d7Da409545E74bD9d4fEaD8365AF0158c43DbA
• VRF coordinator: 0x9d57aB4517ba97349551C876a01a7580B1338909
• deployment transaction: 0x11512ddda3cd3e7ae64bab1cfec1d1e6febb484363af72698c9a1bcdc5183f13
• deployment block: 52660660
• read-only coordinator and relic-storage smoke checks passed

Paired frontend

Use together with CryptoMickle/rise-dungeon-frontend#63. The frontend preview is scoped to this deployment address.