Add Chainlink and Spectra Finance to the ecosystem catalog

[stellar-triage-bot]

🤖 Automated message from the Stellar Triage Bot.

Closes #151

This adds Chainlink under Oracles and Spectra Finance under Yield & Vaults in skills/standards/ecosystem.md. The text follows the issue. It also adds evals/scenarios/standards/05-chainlink-oracle.json, which checks that agents do not treat the Chainlink proxy as SEP-40.

Checks:

• Proxy IDs, reader interface, Round fields and 18-decimal rule match Chainlink's docs source and chainlink-stellar data_feeds_proxy.rs.
• BTC/USD data_id is the same in Chainlink's mainnet and testnet feed lists.
• Both proxies exist on their networks with the same Wasm (stellar.expert).
• Data Streams allowlist and Verifier come from Chainlink's Stellar tutorial.
• Spectra contract list, features and permissionless caveat match its developer docs. Its pools API shows live mainnet markets.
• Spectra's X post (2026-10-14) states the XLM and USDC deposit and swap.
• All links return 200.

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-10-15 15:03 UTC

[stellar-triage-bot]

🤖 Automated message from the Stellar Triage Bot.

Verified at 1fc65d5. Merging now.

• The diff adds two catalog entries and one eval scenario. Nothing else changes.
• Every claim checks out against Chainlink's docs source, chainlink-stellar, Spectra's docs and pools API, and the SDF launch post.
• Both projects are live on mainnet.
• The preview check (lint, type check, build) is green.
• The Copilot review request did not attach, so there is no review to address.