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>

docs/adr/ADR-0003-target-system-hierarchy.md

@@ -35,12 +35,11 @@ We model the system hierarchy explicitly:
 
 - A CUBE contains:
   - HBM + memory controller (HBM_CTRL)
-  - XBAR (top/bottom): HBM pseudo-channel crossbar, PE's dedicated path to HBM
-  - Bridge (left/right): connects XBAR.top ↔ XBAR.bottom for cross-half HBM access
-  - NOC: 2D mesh router grid spanning the entire cube with XY routing and
-    per-segment contention modeling; carries all intra-cube traffic including
-    PE DMA to xbar (HBM), inter-cube (UCIe), command (M_CPU↔PE_CPU), and
-    shared SRAM access. See ADR-0017 for full NOC architecture.
+  - NOC router mesh: 2D grid of explicit routers (from cube_mesh.yaml) with XY routing;
+    carries all intra-cube traffic including HBM data, inter-cube (UCIe),
+    command (M_CPU↔PE_CPU), and shared SRAM access.
+    HBM_CTRL is attached to PE routers (local HBM = 0 hop).
+    See ADR-0017 and ADR-0019 for full architecture.
   - Shared SRAM: cube-level shared memory accessible by all PEs via NOC
   - management/control CPU (M_CPU) coordinating PE command distribution and completion aggregation
   - multiple PEs