[Bug] CI BVT result comparator crashes with NumberFormatException: multiple points

## Problem

The BVT Java result comparator crashes with:

```
java.lang.NumberFormatException: multiple points
```

The stack is in the result-comparison path:

```
RSCell.equals -> RSRow.equals -> StmtResult.equals -> SqlCommand.checkResult
```

Observed in both:

- [PR #28941](https://github.com/matrixorigin/matrixone/pull/28941), run [35001797216](https://github.com/matrixorigin/matrixone/actions/runs/35001797216)
- [PR #28830](https://github.com/matrixorigin/matrixone/pull/28830), run [35001792067](https://github.com/matrixorigin/matrixone/actions/runs/35001792067)

This is a shared BVT harness/result-parsing failure, not a failure in either PR's changed production path.

## Requested investigation

1. Identify the result cell and input value that is parsed as a number with multiple decimal points.
2. Make the comparator report the SQL/case/value clearly instead of crashing.
3. Add a focused harness regression test and verify the affected BVT cases.