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>

components.yaml

@@ -28,9 +28,6 @@ components:
   switch_v1:      kernbench.components.builtin.forwarding:TransitComponent
   noc_v1:         kernbench.components.builtin.forwarding:TransitComponent
   ucie_v1:        kernbench.components.builtin.forwarding:TransitComponent
-  noc_2d_mesh_v1: kernbench.components.builtin.noc:TwoDMeshNocComponent
-  xbar_v1:        kernbench.components.builtin.xbar:PositionAwareXbarComponent
-
   # IO / Host interface
   pcie_ep_v1:     kernbench.components.builtin.pcie_ep:PcieEpComponent
   io_cpu_v1:      kernbench.components.builtin.io_cpu:IoCpuComponent