feat(horizon): expose Provision.delegatedTokensActive as the APR/APY denominator

schema.graphql

@@ -1002,6 +1002,8 @@ type Provision @entity(immutable: false) {
   delegatedTokens: BigInt!
   "Tokens delegated that are thawing from the provision"
   delegatedThawingTokens: BigInt!
+  "Actively-earning delegated tokens: delegatedTokens minus delegatedThawingTokens. This is the correct denominator for delegation APR/APY: it excludes both in-period thawing and completed-but-not-yet-withdrawn delegation, since thawed-but-unwithdrawn tokens remain counted in delegatedThawingTokens until withdrawal. Prefer this over delegatedTokens when computing returns."
+  delegatedTokensActive: BigInt!
   "Total shares of the delegator pool"
   delegatorShares: BigInt!
   "Exchange rate of tokens received for each share"

src/mappings/helpers/helpers.ts

@@ -256,6 +256,7 @@ export function createOrLoadProvision(indexerAddress: Bytes, verifierAddress: By
       provision.delegatorShares = BigInt.fromI32(0)
       provision.delegationExchangeRate = BigInt.fromI32(0).toBigDecimal()
     }
+    provision.delegatedTokensActive = provision.delegatedTokens.minus(provision.delegatedThawingTokens)
     provision.thawingUntil = BigInt.fromI32(0)
     provision.ownStakeRatio = BigInt.fromI32(0).toBigDecimal()
     provision.delegatedStakeRatio = BigInt.fromI32(0).toBigDecimal()
@@ -1168,6 +1169,7 @@ export function calculateOverdelegationDilutionForProvision(provision: Provision
 }
 
 export function updateAdvancedProvisionMetrics(provision: Provision): Provision {
+  provision.delegatedTokensActive = provision.delegatedTokens.minus(provision.delegatedThawingTokens)
   provision.ownStakeRatio = calculateOwnStakeRatioForProvision(provision as Provision)
   provision.delegatedStakeRatio = calculateDelegatedStakeRatioForProvision(provision as Provision)
   provision.indexingRewardEffectiveCut = calculateIndexingRewardEffectiveCutForProvision(provision as Provision)

src/mappings/horizonStaking.ts

@@ -553,6 +553,9 @@ export function handleDelegatedTokensWithdrawn(event: DelegatedTokensWithdrawn):
     // might want to track locked/thawing tokens in provision too
     provision.delegatedTokens = provision.delegatedTokens.minus(event.params.tokens)
     provision.delegatedThawingTokens = provision.delegatedThawingTokens.minus(event.params.tokens)
+    // Withdrawal removes equal amounts from both totals, so the actively-earning base is unchanged;
+    // recompute explicitly to keep the field consistent (this handler bypasses updateAdvancedProvisionMetrics).
+    provision.delegatedTokensActive = provision.delegatedTokens.minus(provision.delegatedThawingTokens)
     provision.save()
 
     let indexerID = event.params.serviceProvider.toHexString()