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/report.py

@@ -137,7 +137,7 @@ def _extract_peaks(spec: dict | None) -> tuple[float, float]:
     gemm_attrs = comps.get("pe_gemm", {}).get("attrs", {})
     peak_tflops = float(gemm_attrs.get("peak_tflops_f16", 0.0))
     cube_links = cube.get("links", {})
-    hbm_bw = float(cube_links.get("xbar_to_hbm_bw_gbs", 0.0))
+    hbm_bw = float(cube_links.get("hbm_to_router_bw_gbs", 0.0))
     return peak_tflops, hbm_bw