[DEV] Improve Kunlun RoPE cluster utilization and native positions #1573

Target version: InfiniLM-v0.2.9c.

Kunlun RoPE uses only eight of P800's twelve clusters, and its worker ordering underutilizes clusters on small inputs. Support cluster-striped workers, device-aware cluster counts and bounded native positions to remove caller preprocessing.

Implementation: PR #1574, limited to the RoPE kernel file. Correctness and performance results are summarized in the PR description; detailed validation materials are retained outside the patch.