apollo_batcher: add ReadPathsAndCommitBlock committer task type

[yoavGrs]

Adds the task input/output variants and their handling in the state
committer under os_input: the task calls the committer's
read_paths_and_commit_block endpoint and currently discards the returned
Patricia witnesses. Nothing constructs the task yet.

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com

blockifier: add len and is_empty to AccessedKeys

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com

[yoavGrs]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• apollo_batcher: persist patricia proofs returned by the committer #14393
• apollo_batcher: route commitment through read_paths_and_commit_block under os_input #14392
• apollo_batcher: persist accessed keys before adding the commitment task #14391
• apollo_batcher: add ReadPathsAndCommitBlock committer task type #14385 👈 (View in Graphite)
• apollo_batcher: refactor commit metrics to read the label from the task output #14384
• apollo_batcher: refactor TaskTimer with a timer map per task label #14383
• apollo_storage: add patricia_proofs table for OS-input witnesses #14382
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[reviewable-StarkWare]

This change is 

[github-actions]

Artifacts upload workflows:

• Started at 2026-06-04T08:44:18Z

[cursor]

PR Summary

Low Risk
Changes are feature-gated and unused in production paths until something constructs the new task; commitment behavior for existing CommitBlock is unchanged.

Overview
Under the os_input feature, the batcher commitment manager gains a ReadPathsAndCommitBlock committer task alongside existing commit/revert tasks. The state committer invokes the committer’s read_paths_and_commit_block API, keeps only the global root for storage (Patricia witnesses are dropped for now), and routes results through the same commitment finalization path as CommitBlock. Revert-wait and metrics treat this variant like a commit; dedicated metrics are deferred.

In blockifier, AccessedKeys adds len and is_empty over storage keys, contracts, and class hashes—supporting logging/sizing for the new task’s accessed-key count. No caller enqueues ReadPathsAndCommitBlock yet; this is plumbing only.

^{Reviewed by Cursor Bugbot for commit 3ee7737. Bugbot is set up for automated code reviews on this repo. Configure here.}