gitea: the tools' token carries write:admin, and a kept token is re-minted when it lacks a scope

The forge's own users are the mesh's to settle — making the builder's login
a site admin so private repos build (hq 229) — and the tools' token had no
write:admin. A token kept from before a scope was added lacks it, so the
client now treats the forge's 403 "required scope" like a 401: the source
re-mints by name with the whole list and retries once. The fake forge in the
tests learns /repos/search, which the client has used since 2026-09-28 and
which had left 9 of the 11 token tests failing on main.

modules/gitea/token.ts

@@ -34,15 +34,21 @@ export const TOKEN_NAME = "mesh-tools";
  *                      It sits under the `user` category despite listing repositories, not `repository`
  *                      — confirmed against the running forge (1.27.3), which answered
  *                      `required=[read:user]` to a token carrying only the other two.
- * Nothing under /admin, /orgs or write:user — the escape-hatch tool reaches only what these three cover.
+ *   write:admin      — /admin/users: the forge's own users are the mesh's to settle, such as making
+ *                      the builder's login a site admin so every repository the mesh may build is
+ *                      clonable (novox/hq 229). Nothing under /orgs or write:user.
+ *
+ * A token kept from before a scope was added lacks it: the forge answers such a call with
+ * `403 token does not have at least one of required scope(s)`, and the client treats that like a
+ * 401 — the source re-mints by name, with the whole list, and the call is retried once.
  */
-export const TOKEN_SCOPES: readonly string[] = ["write:repository", "write:issue", "read:user"];
+export const TOKEN_SCOPES: readonly string[] = ["write:repository", "write:issue", "read:user", "write:admin"];
 
 /** Where a client's token comes from, and what to do when the forge says it is wrong. */
 export interface TokenSource {
   /** The token to authenticate with now; minted, read or configured. */
   current(): Promise<string>;
-  /** The forge answered 401 to `rejected`. A fresh token, or a plain error when there is nothing to renew with. */
+  /** The forge answered 401 to `rejected`, or 403 for a scope it lacks. A fresh token, or a plain error when there is nothing to renew with. */
   renew(rejected: string): Promise<string>;
 }
 
@@ -170,6 +176,11 @@ export class MintedToken implements TokenSource {
     return this.mint("the forge rejected the kept token — minting a fresh one");
   }
 
+  /** What the forge's scoped tokens say when a kept token predates a scope the tools now need. */
+  static lacksScope(status: number, body: string): boolean {
+    return status === 403 && /required scope/i.test(body);
+  }
+
   /** One mint at a time: concurrent first calls share it, rather than each minting its own. */
   private mint(why: string): Promise<string> {
     if (this.inflight === null) {