Remove xbar/noc remnants, rule-based cube-view connectors

- Delete xbar.py and noc.py (TwoDMeshNocComponent) — unused since router mesh
- Remove xbar_v1/noc_2d_mesh_v1 from components.yaml
- Fix pe_to_xbar → pe_to_router in routing exclusion set
- Fix xbar_to_hbm_bw_gbs → hbm_to_router_bw_gbs in report.py
- Update all docstrings/comments referencing xbar/bridge → router mesh
- Cube-view connectors: rule-based _connector_points helper
  - PE↔router: single diagonal line (not chevron)
  - UCIe N/S: 45°→horizontal→45°
  - UCIe E/W: 45°→vertical→45°
  - HBM ports: 45°→horizontal→45°

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/kernbench/cli/probe.py

@@ -116,7 +116,7 @@ def _fmt_util(eff: float, bn: float | None) -> str:
 
 
 def _short_name(node_id: str) -> str:
-    """Shorten node id: keep last 2 segments to avoid ambiguity (xbar.pe0 vs pe0)."""
+    """Shorten node id: keep last 2 segments to avoid ambiguity (router.pe0 vs pe0)."""
     parts = node_id.split(".")
     return ".".join(parts[-2:]) if len(parts) >= 2 else node_id
 
@@ -366,7 +366,7 @@ def run_probe(topology_path: str, case_filter: str | None = None) -> int:
 
     # --- PE DMA Summary Table ---
     print()
-    print(f"=== PE DMA Latency (pe_dma -> xbar -> HBM, data={nbytes}B) ===")
+    print(f"=== PE DMA Latency (pe_dma -> router -> HBM, data={nbytes}B) ===")
     print(f"  {'Case':<26} {'Target':<28} {'Actual':>8}"
           f"  {'Ovhd':>6} {'Drain':>6} {'Wire':>5} {'Ovhd%':>6} {'Drain%':>7}"
           f"   {'Eff.BW':>8}   {'BN.BW':>8}   {'Util%':>6}")