chore: update tx_service for deferred scan read release

[liunyl]

Context

Companion to merged eloqdata/tx_service#526 and eloqdata/tx_service#508. EloqKV consumes the fix through the data_substrate submodule.

Behavior before and after

Before: later hash-scan batches could redundantly re-enter an already completed CC-map memory source while store buckets were unfinished.

After: scan ownership remains until transaction finalization, and completed hash memory sources are skipped without adding another ReadIntent.

Implementation

Advance data_substrate to tx_service main commit 87ed815, the squash-merge result of eloqdata/tx_service#526. No EloqKV source code changes.

Design decisions and alternatives

Keep the engine fix entirely in tx_service; EloqKV only updates the gitlink.

Test plan

• tx_service unit/CTest coverage
• Formatting/build checks
• EloqKV CI completion

Commands and results:

env LD_LIBRARY_PATH=/data/workspace/eloqkv/data_substrate/third_party/install/lib ./bld/tx_service/tests/TxConsistency-Test
# 121 assertions passed

git diff --check origin/main...HEAD
# passed

The final EloqKV CI run was triggered before merge. The required cpplint and formatting checks passed; remaining integration jobs were still running when merged per maintainer direction.

Risk assessment

No EloqKV API, protocol, WAL, storage-format, or configuration changes. Runtime risk is limited to the tx_service scan behavior reviewed and tested in #526.

Rollback plan

Revert this gitlink update.

Reviewer guide

Verify data_substrate points to 87ed815, which is reachable from tx_service main.

Follow-up work

None.

[coderabbitai]

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Walkthrough

The data_substrate subproject reference changes from commit 9cd8840d71fece0ef61de85c51050f7355411fde to f23e1e8e46e58b81e10338df606adf01419f38d8. No other code changes are present.

Changes

Data substrate update

Layer / File(s)	Summary
Update subproject pointer data_substrate	The recorded data_substrate commit reference is updated to a new SHA.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Possibly related PRs

• eloqdata/eloqkv#286 — Updates the same data_substrate submodule reference.
• eloqdata/eloqkv#313 — Bumps the same submodule pointer without other code changes.
• eloqdata/eloqkv#517 — Updates the pinned data_substrate commit.

Suggested labels: trigger-ci

Suggested reviewers: mrguin

Poem

A rabbit hops past hashes bright,
One substrate pointer shifts tonight.
No code is stirred, no branches bend,
One new commit marks the end.
🐇✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly matches the main change: advancing the tx_service submodule for deferred scan read release.
Description check	✅ Passed	The description closely follows the template and covers context, behavior, implementation, testing, risks, rollback, reviewer guidance, and follow-up work.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/issue-508-defer-read-release

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@data_substrate`:
- Line 1: Update the data_substrate gitlink from
c833ee20a64c7d4d3c50664f642eb33934d3eb33 to the finalized tx_service#526
squash-merge commit 3427a03.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: c21b2a1b-0bc8-43d0-a65b-22ce58d4d47c

📥 Commits

Reviewing files that changed from the base of the PR and between 922f68d and c22be12.

📒 Files selected for processing (1)

• data_substrate