M_CPU/SRAM placement via pos_mm in topology.yaml (nearest router)

Component placement uses mm coordinates in topology.yaml, mesh_gen
finds the nearest router automatically. M_CPU moved to pos_mm=[7.5,2.0]
(→ r0c2), SRAM at pos_mm=[1.5,9.0] (→ r3c0).

No hardcoded router references in topology config.

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

tests/test_topology_compile.py

@@ -158,9 +158,9 @@ def test_pe_dma_to_router():
 def test_command_path_m_cpu_router_pe_cpu():
     es = _edge_set(_graph())
     cp = "sip0.cube0"
-    # m_cpu <-> r2c0 (bidirectional command)
-    assert (f"{cp}.m_cpu", f"{cp}.r2c0") in es
-    assert (f"{cp}.r2c0", f"{cp}.m_cpu") in es
+    # m_cpu <-> r0c2 (bidirectional command)
+    assert (f"{cp}.m_cpu", f"{cp}.r0c2") in es
+    assert (f"{cp}.r0c2", f"{cp}.m_cpu") in es
     # router -> pe_cpu for each PE (command kind)
     assert (f"{cp}.r0c0", f"{cp}.pe0.pe_cpu") in es
     assert (f"{cp}.r5c5", f"{cp}.pe7.pe_cpu") in es
@@ -416,8 +416,8 @@ def test_cube_view_hbm_router():
 
 
 def test_cube_view_m_cpu_router():
-    """Cube view: m_cpu connects to its router r2c0."""
+    """Cube view: m_cpu connects to its router r0c2."""
     v = _graph().cube_view
     ves = {(e.src, e.dst) for e in v.edges}
-    assert ("m_cpu", "r2c0") in ves
-    assert ("r2c0", "m_cpu") in ves
+    assert ("m_cpu", "r0c2") in ves
+    assert ("r0c2", "m_cpu") in ves