feat: add product concept subtitle to radars

A Radar gains an optional Concept — a short subtitle naming the product
and its typical performances, rendered under the title and wrapping to a
balanced second line when long. Old radars default to an empty Concept
on load.

tsconfig.json

@@ -1,7 +1,4 @@
 {
   "files": [],
-  "references": [
-    { "path": "./tsconfig.app.json" },
-    { "path": "./tsconfig.node.json" }
-  ]
+  "references": [{ "path": "./tsconfig.app.json" }, { "path": "./tsconfig.node.json" }]
 }