gloas DA checks

[mehdi-aouadi]

PR Description

Add Gloas fork choice util da check

Fixed Issue(s)

partially #10377

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.

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Note

Medium Risk
Touches fork-choice and execution payload import flow by changing how post-state is retrieved and when data-availability checks are initiated, which could impact block/payload processing across Gloas+ milestones if incorrect.

Overview
Adds Gloas support for data-column sidecar data-availability checking by wiring dataColumnSidecarAvailabilityCheckerFactory into ForkChoiceUtilGloas and treating GLOAS/HEZE like FULU for block DA checks.

Simplifies availability-checker APIs by removing the execution-payload-specific ForkChoiceUtil.createAvailabilityChecker(SignedExecutionPayloadEnvelope) path; execution payload imports now load the full SignedBlockAndState (via new RecentChainData.retrieveBlockAndState and EmptyStoreResults.EMPTY_SIGNED_BLOCK_AND_STATE_FUTURE) and run DA checks against the associated SignedBeaconBlock instead.

Also updates .gitignore to ignore the full .claude/ directory.

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