Optimized Python can relabel inconsistent table fields

### Feature Summary

Table construction validates row field names with an assert. Optimized Python removes that validation, so values from later rows can be assigned the first row's field names.

Before: inconsistent row fields -> later values are silently relabeled

After: inconsistent row fields -> ValueError prevents data corruption

Reproduction evidence:

Run optimized Python and construct a table whose first row has field expected and second row has field different. The second row is returned under expected without an error.

Version and commit evidence:

1.3.0-incubating-SNAPSHOT (main)

**Commit Hash**

70c21145887920528d7d5540e3fb790b43e8b759

**What browsers are you seeing the problem on?**

Not browser-specific.

**Relevant log output**

optimized=True, columns=[expected], second row={expected: 2}, error_raised=False

### Proposed Solution or Design

After: inconsistent row fields -> ValueError prevents data corruption

### Affected Area

Workflow Engine (Amber)