fix: claimed in staking info endpoint

docs/src/openapi-v1.yaml

@@ -2656,8 +2656,13 @@ components:
         stakingLedger:
           $ref: '#/components/schemas/StakingLedger'
       description: >-
-        Note: Runtime versions of Kusama less than 1062 will either have `lastReward` in place of
-        `claimedRewards`, or no field at all. This is related to changes in reward distribution. See: [Lazy Payouts](https://github.com/paritytech/substrate/pull/4474), [Simple Payouts](https://github.com/paritytech/substrate/pull/5406)
+        Note: After Sidecar's v.20.0.0, we always return the field `claimedRewards` under `stakingLedger`.
+        Before we returned `lastReward`, `claimedRewards` or `legacyClaimedRewards`. While these fields (and their corresponding calls)
+        are still taken into account, they are now only used in the background to calculate the right values for the `claimedRewards` field.
+        Note on lastReward: Runtime versions of Kusama less than 1062 will either have `lastReward` in place of
+        `claimedRewards`, or no field at all. This is related to changes in reward distribution.
+        See: [Lazy Payouts](https://github.com/paritytech/substrate/pull/4474),
+        [Simple Payouts](https://github.com/paritytech/substrate/pull/5406)
     AccountStakingPayouts:
       type: object
       properties:
@@ -4259,11 +4264,27 @@ components:
           format: unsignedInteger
         claimedRewards:
           type: array
-          description: Array of eras for which the stakers behind a validator have
-            claimed rewards. Only updated for _validators._
+          description: Array of objects, each containing an `era` and its corresponding `status`,
+            which represents the rewards status of the stakers backing a validator. Only updated
+            for _validators._ This array is populated with values from `stakingLedger.legacyClaimedRewards`
+            or `stakingLedger.claimedRewards`, as well as the `query.staking.claimedRewards` call, depending
+            on whether the queried block is before or after the migration. For more details on the implementation
+            and the migration, refer to the related PR (https://github.com/paritytech/substrate-api-sidecar/pull/1445)
+            and linked issue (https://github.com/paritytech/substrate-api-sidecar/issues/1433#issuecomment-2075914389).
           items:
-            type: string
-            format: unsignedInteger
+            type: object
+            properties:
+              era:
+                type: string
+                description: The era for which we check the rewards status.
+                format: unsignedInteger
+              status:
+                type: string
+                description: The rewards status of the stakers backing a validator.
+                enum:
+                - claimed
+                - unclaimed
+                - partially claimed
       description: The staking ledger.
     StakingProgress:
       type: object