v3: added site-wide categories, added admin category management, various visual fixes

api/lib/permissions.ts

@@ -6,13 +6,15 @@ export type Permission =
   | "dump:moderate"
   | "comment:moderate"
   | "playlist:moderate"
-  | "user:manage";
+  | "user:manage"
+  | "category:manage";
 
 const ALL_PERMISSIONS: readonly Permission[] = [
   "dump:moderate",
   "comment:moderate",
   "playlist:moderate",
   "user:manage",
+  "category:manage",
 ];
 
 // Roles are fixed in code. `admin` is a superset of every permission (current

api/lib/reserved-slugs.ts

@@ -0,0 +1,33 @@
+// Top-level path segments that already have meaning in the SPA router
+// (see src/App.tsx) plus a few reserved for infrastructure. Category slugs
+// live at the URL root (e.g. /music), so they must never collide with these.
+export const RESERVED_SLUGS: readonly string[] = [
+  "~",
+  "dumps",
+  "users",
+  "playlists",
+  "search",
+  "login",
+  "register",
+  "notifications",
+  "reset-password",
+  "manage",
+  "api",
+  "assets",
+];
+
+// Lowercase alphanumerics, hyphen-separated, no leading/trailing/double hyphen.
+export const CATEGORY_SLUG_RE = /^[a-z0-9]+(?:-[a-z0-9]+)*$/;
+
+export function isValidSlugFormat(slug: string): boolean {
+  return CATEGORY_SLUG_RE.test(slug);
+}
+
+export function isReservedSlug(slug: string): boolean {
+  return RESERVED_SLUGS.includes(slug);
+}
+
+/** A slug is available when it is well-formed and not reserved. */
+export function isSlugAvailable(slug: string): boolean {
+  return isValidSlugFormat(slug) && !isReservedSlug(slug);
+}