Add pointer infospace for the first-wave architecture collection

Five system entities reference owning-repo documents. No copied bodies.

canon/architecture/infospace/infospace.yaml

@@ -0,0 +1,16 @@
+topic:
+  name: Coulomb estate architecture
+  domain: architecture
+  sources: entities/
+
+disciplines:
+  - name: arc42
+    path: discipline/
+
+entities_dir: entities
+
+viability:
+  redundancy_ratio:
+    max: 0.2
+  coverage_ratio:
+    min: 0.5