feat(web): settings view for roots and policies

Own route beside library and queues. Roots edit kind, audience, path
and their policy; policies get a form over the real fields — size
bands as number inputs, score and source weights as numbers,
resolution preference and audio/HDR rules as validated lists. Delete
arms before firing; a 409 from a referenced policy or occupied root
surfaces its message.

web/src/router.ts

@@ -6,6 +6,7 @@ export type Route =
   | { kind: "board" }
   | { kind: "library" }
   | { kind: "queues" }
+  | { kind: "settings" }
   | { kind: "search"; query: string }
   | { kind: "releases"; movieId: number };
 
@@ -17,6 +18,9 @@ export function parseRoute(url: URL): Route {
   if (segments.length === 1 && segments[0] === "queues") {
     return { kind: "queues" };
   }
+  if (segments.length === 1 && segments[0] === "settings") {
+    return { kind: "settings" };
+  }
   if (segments.length === 1 && segments[0] === "search") {
     const query = url.searchParams.get("q") ?? "";
     return query === "" ? { kind: "board" } : { kind: "search", query };
@@ -38,6 +42,8 @@ export function routePath(route: Route): string {
       return "/library";
     case "queues":
       return "/queues";
+    case "settings":
+      return "/settings";
     case "search":
       return `/search?q=${encodeURIComponent(route.query)}`;
     case "releases":