Schedule block production duties for next epoch in fulu

[rolfyone]

This is stable post-fulu, so we can avoid the slot 0 issue.

fixes #10124

Documentation

• I thought about documentation and added the doc-change-required label to this PR if updates are required.

Changelog

• I thought about adding a changelog entry, and added one if I deemed necessary.

---

Note

Abstracts duty lookahead and enables block proposer duties to be scheduled one epoch ahead from FULU onward, updating implementations and tests.

• Core (validator client):
  • AbstractDutyScheduler: remove fixed lookAheadEpochs config; introduce abstract int getLookAheadEpochs(UInt64) and use it in calculateDuties and isAbleToVerifyEpoch; make spec protected.
• Block duties:
  • BlockDutyScheduler: implement dynamic lookahead (0 before FULU, 1 from FULU); add debug logging; adjust constructor usage.
• Attestations:
  • AttestationDutyScheduler: override getLookAheadEpochs to constant 1; update constructor.
• Tests:
  • BlockDutySchedulerTest: add/adjust tests for milestone-dependent lookahead; update references to dynamic getLookAheadEpochs and specs.

^{Written by Cursor Bugbot for commit 77cfe6c. This will update automatically on new commits. Configure here.}

[tbenr]

Apart of the compilation issue, I tried locally and I get:

2025-11-14 13:43:05.016 INFO  - Epoch Event *** Epoch: 4, Justified checkpoint: 3, Finalized checkpoint: 2, Finalized root: deca9232918b8269c97039fca968be979044b31f91a7fb0e5f09df3fe5855502
2025-11-14 13:43:05.016 ERROR - Failed to request validator duties for epoch 5. Retrying after delay.
java.lang.IllegalArgumentException: Proposer duties were requested for a future epoch (current: 4, requested: 5).
at tech.pegasys.teku.validator.coordinator.ValidatorApiHandler.getProposerDuties(ValidatorApiHandler.java:320) ~[classes/:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at tech.pegasys.teku.infrastructure.events.DirectEventDeliverer.executeMethod(DirectEventDeliverer.java:74) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.DirectEventDeliverer.deliverToWithResponse(DirectEventDeliverer.java:67) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.AsyncEventDeliverer.lambda$deliverToWithResponse$1(AsyncEventDeliverer.java:80) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.AsyncEventDeliverer$QueueReader.deliverNextEvent(AsyncEventDeliverer.java:125) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.AsyncEventDeliverer$QueueReader.run(AsyncEventDeliverer.java:116) ~[classes/:?]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[?:?]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[?:?]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
2025-11-14 13:43:05.017 INFO  - Calling local execution layer to start block production (block slot: 32)

[rolfyone]

Apart of the compilation issue, I tried locally and I get:

2025-11-14 13:43:05.016 INFO  - Epoch Event *** Epoch: 4, Justified checkpoint: 3, Finalized checkpoint: 2, Finalized root: deca9232918b8269c97039fca968be979044b31f91a7fb0e5f09df3fe5855502
2025-11-14 13:43:05.016 ERROR - Failed to request validator duties for epoch 5. Retrying after delay.
java.lang.IllegalArgumentException: Proposer duties were requested for a future epoch (current: 4, requested: 5).
at tech.pegasys.teku.validator.coordinator.ValidatorApiHandler.getProposerDuties(ValidatorApiHandler.java:320) ~[classes/:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at tech.pegasys.teku.infrastructure.events.DirectEventDeliverer.executeMethod(DirectEventDeliverer.java:74) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.DirectEventDeliverer.deliverToWithResponse(DirectEventDeliverer.java:67) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.AsyncEventDeliverer.lambda$deliverToWithResponse$1(AsyncEventDeliverer.java:80) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.AsyncEventDeliverer$QueueReader.deliverNextEvent(AsyncEventDeliverer.java:125) ~[classes/:?]
at tech.pegasys.teku.infrastructure.events.AsyncEventDeliverer$QueueReader.run(AsyncEventDeliverer.java:116) ~[classes/:?]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[?:?]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[?:?]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
2025-11-14 13:43:05.017 INFO  - Calling local execution layer to start block production (block slot: 32)

ok cool - i had meant as draft as some of the AT im curious about...

i had run locally, was this remote validator or inbuilt?