chore(core): name --kv-bits in the bits validation error instead of the internal struct #1629

Summary

The --kv-bits validation error message leaks the internal config struct name instead of naming the CLI flag, unlike every other arm in the same match.

Background

src/lib/mlxcel-core/src/cache/batch_quant.rs:325-328 reads:

"BatchKvQuantConfig: bits must be non-negative (got {})"

while the very next arm at lines 331-334 correctly says:

"--kv-group-size must be positive, got {}"

The remaining arms in the same match (verified around lines 340-360) all use flag spellings with the , got {} punctuation.

Proposed Solution

Change the one format string to name --kv-bits and match the surrounding , got {} style.

Implementation Notes

• Pure string edit, no logic change.

Acceptance Criteria

• The bits-validation error names --kv-bits and follows the same punctuation as the sibling arms.
• Tests pass.

Original Suggestion

Title: chore(core): --kv-bits validation error names an internal struct instead of the flag

The --kv-bits validation error message leaks the internal config struct name instead of naming the CLI flag, unlike every other arm in the same match.

Evidence

src/lib/mlxcel-core/src/cache/batch_quant.rs:325-328 reads:

"BatchKvQuantConfig: bits must be non-negative (got {})"

while the very next arm at lines 331-334 correctly says:

"--kv-group-size must be positive, got {}"

and the remaining arms in the same match (lines 347-360) all use flag spellings with the , got {} punctuation.

Suggested fix

Change the one format string to name --kv-bits and match the surrounding , got {} style. Pure string edit, no logic change.

Acceptance criteria

• The bits-validation error names --kv-bits and follows the same punctuation as the sibling arms
• Tests pass