Add versioned HTTP API routes

docs/ARCHITECTURE.md

@@ -93,11 +93,11 @@ HTTP is the primary integration contract for:
 
 Preferred direction:
 
-    GET  /status
-    GET  /config
-    POST /relay/set
+    GET  /api/v1/status
+    GET  /api/v1/config
+    POST /api/v1/relay/set
 
-Future versioning may move to /api/v1.
+Pre-versioned root routes remain registered as compatibility aliases for existing local clients.
 
 ## Generic IDs