Studio 4.8.1: explain structural misfits

Patch release prompted by a real user report: a 2.8T-parameter model on 8x TP8 workers showed every GPU at 127% with no clear reason and a misleading 'add workers' suggestion.

• When one TP replica cannot hold a single copy of the model, the verdict, the reading panel and a new top-ranked recommendation now explain it directly: each TP group is a full copy of the weights, so adding workers adds demand as fast as capacity. The recommendation names the minimum TP that would fit, the largest weight quant that fits at the current TP, higher-VRAM parts, and notes that pipeline parallelism is not modeled.
• 'Add workers' is suppressed when it cannot help. Queueing guidance and the 'balanced configuration' insight no longer appear on non-fitting configurations.