Add support for the latest environments (add devnet, retire summit/w3s)

Summary

Add support for the latest environments in the tutorial: add the new devnet preset, retire the removed summit / w3s environment, and keep the paseo naming unambiguous.

Background

The environment set changed. The summit environment was removed, and a new devnet preset was added. The reference for the exact values is contract-dependency-manager PR #61 (https://github.com/paritytech/contract-dependency-manager/pull/61).

Key facts from that change:

• devnet: the public products devnet on the Paseo testnet Asset Hub (para 1000, EVM chain id 420420417), wired to the community operated ContractRegistry at 0x59b0245778917af55224e5f8fb55f7f8d452619f. It uses the devnet-asset-hub / devnet-bulletin descriptors, the Bulletin RPC wss://bulletin-paseo.tservices.es:8443, and getChainAPI("devnet").
• summit / w3s: removed upstream. Anything selecting summit or w3s needs to move off it.
• paseo: the paseo preset targets paseo-next (para 1500), not the Paseo testnet.

What needs to happen

• Point the quests at devnet using the devnet-asset-hub / devnet-bulletin descriptors and getChainAPI("devnet").
• Remove any summit / w3s references in the quest config and copy.
• Make sure the quest text refers to paseo-next where it means paseo-next, not the Paseo testnet.
• Update quests.json and any prebuilt artifacts (for example dist.bulletin.car) if they embed an environment.

Acceptance criteria

• Every quest that touches a chain runs against devnet.
• No summit / w3s references remain.
• Environment naming in the tutorial is accurate.

Start by reviewing contract-dependency-manager PR #61 and searching the quest configuration and copy for environment references. Update quests.json and any embedded environment artifacts such as dist.bulletin.car, then verify that chain quests use devnet, summit/w3s references are gone, and paseo naming distinguishes paseo-next from the Paseo testnet.