feat(jolt-akita): Refactor Akita adapter and lattice opening semantics

[sumchecker]

Summary

• Narrow jolt-akita toward a native PCS adapter surface by hiding internal Akita config/layout/sparse types and exposing only focused adapter APIs.
• Align Stage 8 lattice precommitted openings with the spec: original commitment handles, object-local points/layout digests, exact-D validation, and explicit packed vs precommitted routing.
• Split packing proofs into explicit Direct and Packed variants so precommitted Akita openings are first-class direct/native proofs rather than packed proofs with missing reductions.

Reviewer Notes

• This intentionally leaves broad diff-readability/file-splitting work for a later PR.
• Known remaining cleanup: more generic sparse packing-source logic can move from jolt-verifier into jolt-openings, and Stage 8 routing can eventually be isolated further.

Test Plan

• cargo clippy -p jolt-verifier -q --all-targets --features akita -- -D warnings
• cargo clippy -p jolt-openings -q --all-targets -- -D warnings
• cargo nextest run --release -p jolt-verifier --cargo-quiet --features akita -E 'test(akita) or test(precommitted_opening_batches_require_exact_ordered_proofs) or test(clear_batch_rejects_precommitted_count_before_main_proof)'
• cargo nextest run --release -p jolt-openings --cargo-quiet packing

[github-actions]

Warning

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