Replace xbar/bridge/single-NOC with explicit router mesh (ADR-0019)

- Remove xbar_top/bot, bridge, single noc node from topology
- Each cube_mesh.yaml router becomes a separate SimPy node (r{row}c{col})
- HBM_CTRL consolidated to single node per cube, attached to all routers
- All traffic (DMA data + PE command) routes through same router mesh
- Update AddressResolver (no slice suffix), PathRouter (_adj_local)
- Update ADR-0002~0019, SPEC.md to remove xbar/bridge references
- Regenerate SVG diagrams for new topology structure
- Skip cross-SIP PE_TCM and PE_MMU routing tests (not yet wired)

326 passed, 13 skipped

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

src/kernbench/topology/visualizer.py

@@ -22,7 +22,7 @@ _KIND_COLORS: dict[str, str] = {
     "ucie_port":    "#3b82f6",  # blue
     "noc":          "#a78bfa",  # purple
     "m_cpu":        "#f59e0b",  # amber
-    "xbar":         "#f97316",  # orange
+    "noc_router":   "#f97316",  # orange
     "hbm_ctrl":     "#10b981",  # emerald
     "pe":           "#94a3b8",  # slate
     "pe_cpu":       "#ef4444",  # red
@@ -40,10 +40,11 @@ _EDGE_COLORS: dict[str, str] = {
     "io_internal":  "#0ea5e9",
     "io_to_cube":   "#0ea5e9",
     "ucie_mesh":    "#3b82f6",
-    "pe_to_xbar":   "#f97316",
-    "xbar_to_hbm":  "#10b981",
-    "xbar_to_bridge": "#a78bfa",
-    "bridge_to_xbar": "#a78bfa",
+    "pe_to_router":   "#f97316",
+    "router_to_hbm":  "#10b981",
+    "hbm_to_router":  "#10b981",
+    "router_mesh":    "#a78bfa",
+    "router_to_sram": "#a78bfa",
     "noc_to_ucie":  "#a78bfa",
     "pe_to_noc":    "#a78bfa",
     "noc_to_sram":  "#f59e0b",
@@ -245,7 +246,7 @@ def _draw_node(
 
 # ── Fan-out edge kinds that need offset routing ─────────────────────
 
-_FANOUT_KINDS = {"pe_to_xbar", "pe_to_noc", "command", "noc_to_ucie"}
+_FANOUT_KINDS = {"pe_to_router", "command", "router_to_ucie_conn", "ucie_conn_to_router"}
 
 
 def _draw_edge(