Fix query TVList snapshot race during working memtable reads

[shuwenwei]

Summary

• Capture the sorted state and row count under the TVList monitor when preparing a working memtable TVList for query.
• Keep the query-visible row count consistent with the sorted snapshot so later query sorting does not mutate indices beyond an older iterator snapshot.

Root Cause

The query context lock only protects query ownership metadata, not TVList row count, sorted state, writes, or sort operations. A query could share a currently sorted mutable working TVList while recording a row count from a different moment, allowing a later query sort to reorder indices used by an older iterator.

Validation

Not run, per local workflow instruction.

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud