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/components/builtin/pe_dma.py

@@ -96,7 +96,7 @@ class PeDmaComponent(PeEngineBase):
                 request=sub_request, path=path, step=0,
                 nbytes=cmd.nbytes, done=sub_done, drain_ns=drain_ns,
             )
-            # Send to next hop (path[0] is pe_dma itself, path[1] is xbar)
+            # Send to next hop (path[0] is pe_dma itself, path[1] is router)
             if len(path) > 1:
                 yield self.out_ports[path[1]].put(sub_txn.advance())
         # DMA channel released after issue