Summary

This PR integrates Kong's pre-computed estimated APRs into yDaemon for V2 vaults with Curve, Convex, Velodrome, and Aerodrome strategies. The implementation prioritizes Kong's estimated APR data over local RPC-based calculations, reducing RPC call volume and improving performance while maintaining full backward compatibility with the existing API.

Closes #560

How to review

1. Type definitions: Start with internal/models/vaults.go and internal/kong/client.go to review the new TKongEstimatedApr and TKongEstimatedAprComponents types
2. GraphQL query updates: Check internal/kong/client.go for the expanded performance.estimated query
3. Data extraction: Review internal/indexer/indexer.kong.go to see how estimated APR data is extracted from Kong responses
4. Storage accessor: Check internal/storage/elem.vaults.go for the new GetKongEstimatedAPY() function
5. Priority logic: Review processes/apr/main.go to see the Kong-first fallback pattern for Curve and Velo vaults
6. Conversion helper: Check processes/apr/forward.curve.helpers.go for convertKongEstimatedAprToForwardAPY()
7. Documentation: Review docs/apr-oracle-integration.md for the new V2 integration section

Test plan

Manual testing

Verified integration with live yDaemon instance:

Query vault on Ethereum mainnet (Curve vault):

curl -s http://localhost:8080/1/vaults/0xf165a634296800812B8B0607a75DeDdcD4D3cC88 | jq '{address, name: .token.name, type: .apr.forwardAPR.type, netAPR: .apr.forwardAPR.netAPR, composite: .apr.forwardAPR.composite}'

Result:

{
  "address": "0xf165a634296800812B8B0607a75DeDdcD4D3cC88",
  "name": "reUSD/scrvUSD",
  "type": "crv",
  "netAPR": 0.04918341021632009,
  "composite": {
    "boost": 2.2711417165483674,
    "poolAPY": 0.008,
    "boostedAPR": 0.04620378912924455,
    "baseAPR": 0.03806021027585871,
    "cvxAPR": 0,
    "rewardsAPR": 0
  }
}

Verify Kong source data:

curl -s "https://kong.yearn.farm/api/gql" -H "Content-Type: application/json" -d '{"query":"query { vault(chainId: 1, address: \"0xf165a634296800812B8B0607a75DeDdcD4D3cC88\") { address performance { estimated { apr apy type components { boost poolAPY boostedAPR baseAPR rewardsAPY cvxAPR keepCRV } } } } }"}' | jq '.data.vault.performance.estimated'

Kong response (matches yDaemon output exactly):

{
  "apr": 0.04918341021632009,
  "apy": 0.04918341021632009,
  "type": "crv",
  "components": {
    "boost": 2.2711417165483674,
    "poolAPY": 0.008,
    "boostedAPR": 0.04620378912924455,
    "baseAPR": 0.03806021027585871,
    "rewardsAPY": 0,
    "cvxAPR": 0,
    "keepCRV": 0
  }
}

✅ Verification: yDaemon successfully consumes Kong's estimated APR data. All values match exactly, confirming the integration works as expected.

• Manual: Tested with live yDaemon instance on chain 1
• Verified Kong data source matches yDaemon output
• Confirmed backward compatibility (API response structure unchanged)