Restore HC-Tree journal mode with read-only commit handling

[tylerkaraszewski]

Details

This reverts the revert and restores HC-Tree journal mode.

This will show you the diff between the original (reverted) PR and this PR:
c61278b...18dbe1b

We would broadcast a blank entry with commit ID 0 even when leader didn't actually commit anything (because it started a transaction that never attempted to write). This change now correctly skips sending that to followers.

Fixed Issues

For https://github.com/Expensify/Expensify/issues/337537

Tests

AI Tests

Rebuilt Bedrock and Auth after restoring the original test harness, with Auth at the failing CI revision 50c9499605. The original harness enables experimental mode for this run:

expensidev-2404->Auth/test (main) > BEDROCK_DIR=/vagrant/Bedrock.worktrees/tyler-hctree-journal-reland ./authtest -only ACHReimbursement -threads 1 -enableHctree -v -logLevel INFO
HCTree enabled
--------------
✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓✓
[ TEST RESULTS ] Passed: 68, Failed: 0

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-05T20:45:24.283939Z	5b7dede	PR opened

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[tylerkaraszewski]

Opened the Auth test compatibility PR to accompany the HC-Tree journal re-land. It makes local Auth test handles use the same journal mode as the test servers and removes the query-plan test's dependency on the legacy journal table. It also builds against Bedrock without native-journal support.

The affected fixtures passed 33/33 in all four combinations of Bedrock main/re-land and WAL2/HC-Tree. ACH and encryption passed 82/82 with native journals, and the full WAL2 suite passed 13,195/13,195.

The full native suite still has 30 failures: 29 in GetStarredReportList fixtures and one in SearchFiltersTest::testWithdrawalStatusFilter. That run reproduced the read-corruption error during concurrent account creation and a shutdown hang that required terminating the stuck Bedrock child to obtain the final summary. Those remain unresolved; the Auth PR records the results and reproduction commands.