Cube-view: angle HBM lines, offset M_CPU/SRAM blocks

- HBM connection lines angled 30% toward HBM center (not vertical)
  to distinguish from mesh links
- M_CPU/SRAM blocks placed to the left of their router
  with horizontal connector lines (avoid mesh overlap)

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

src/kernbench/topology/visualizer.py

@@ -603,8 +603,12 @@ def _render_cube_view_svg(view: ViewGraph, spec: dict) -> str:
                     bx, by = bx_base + 4, py + offset_x - blk_h / 2
                 else:
                     bx, by = px + offset_x - blk_w / 2, py - r_size - blk_h - 4
+            elif kind in ("mcpu", "sram"):
+                # M_CPU/SRAM: place to the left of router (avoid mesh overlap)
+                bx = px - r_size - blk_w - 6
+                by = py - blk_h / 2 + bi * (blk_h + 2)
             else:
-                # PE/M_CPU/SRAM: place above (top half) or below (bottom half)
+                # PE: place above (top half) or below (bottom half)
                 bx = px + offset_x - blk_w / 2
                 if is_top:
                     by = py - r_size - blk_h - 4 - bi * (blk_h + 2)
@@ -651,8 +655,15 @@ def _render_cube_view_svg(view: ViewGraph, spec: dict) -> str:
                         f'x2="{px + r_size:.0f}" y2="{py:.0f}" '
                         f'stroke="{style["stroke"]}" stroke-width="1" opacity="0.6"/>'
                     )
+            elif kind in ("mcpu", "sram"):
+                # Horizontal connector (block right edge → router left edge)
+                parts.append(
+                    f'  <line x1="{bx + blk_w:.0f}" y1="{by + blk_h / 2:.0f}" '
+                    f'x2="{px - r_size:.0f}" y2="{py:.0f}" '
+                    f'stroke="{style["stroke"]}" stroke-width="1" opacity="0.6"/>'
+                )
             else:
-                # Vertical connector
+                # Vertical connector (PE above/below router)
                 ly1 = by + blk_h if is_top else by
                 ly2 = py - r_size if is_top else py + r_size
                 parts.append(
@@ -674,6 +685,8 @@ def _render_cube_view_svg(view: ViewGraph, spec: dict) -> str:
             )
 
     # ── Router → HBM_CTRL lines (drawn last, on top of everything) ──
+    # Lines go from router to the HBM zone edge, angled toward HBM center
+    # to visually distinguish from vertical mesh links
     for rkey, rval in routers.items():
         if rval is None:
             continue
@@ -683,12 +696,13 @@ def _render_cube_view_svg(view: ViewGraph, spec: dict) -> str:
         r_edge_y = py + r_size if py < hbm_y else py - r_size
         if abs(r_edge_y - hbm_edge_y) > 10:
             has_pe = any(a.endswith(".dma") for a in rval.get("attach", []))
-            # PE routers: thicker, more visible
             sw = "1.5" if has_pe else "0.7"
-            op = "0.6" if has_pe else "0.2"
+            op = "0.6" if has_pe else "0.15"
+            # Angle toward HBM center x (hcx) — slight offset, not fully straight
+            dx = (hcx - px) * 0.3  # 30% pull toward center
             parts.append(
                 f'  <line x1="{px:.0f}" y1="{r_edge_y:.0f}" '
-                f'x2="{px:.0f}" y2="{hbm_edge_y:.0f}" '
+                f'x2="{px + dx:.0f}" y2="{hbm_edge_y:.0f}" '
                 f'stroke="#10b981" stroke-width="{sw}" opacity="{op}" '
                 f'stroke-dasharray="4,3"/>'
             )