Clear stale meter-brand suggestions on retake and skip #94

Follow-up from PR #89, review comment #89 (comment).

At 916838f, retakeCloseUp, skipCloseUp, and close-up entry clear meterNumber but can retain the prior meterBrand suggestion. Retake followed by skip leaves the old suggestion beside a skipped number. No current scene or packet export consumes it, so this is local state cleanup, not a transmission defect.

Clear the brand alongside the number in the real and demo engines, and add a retake-then-skip assertion. Preserve number candidates when the explicit brand-reject action is used.

The manager explicitly deferred this P3 under the 11:00 CDT convergence rule. It does not block #89 integration once the 6.68 focus threshold, 44-point reject width, and required checks pass.