ombi: adopt the Plex entry that plex itself answers for

ace's ombi holds one Plex entry, loaded from an older server and later
retyped to plex's public name: its stored machineIdentifier is not plex's,
while its address answers as plex. Matching by identifier alone would leave
it and add a second entry for the same server.

When no entry carries the server's identifier, each entry's own address is
asked for /identity, and an entry plex answers for is adopted: the bound
connection laid over, and the identifier corrected (ombi builds its "view in
Plex" links from it). Its name, libraries and every other choice stay. An
entry that cannot be asked, or answers as another server, is left alone;
nothing is guessed. Every call of the step is now bounded, since an entry may
name a host that no longer answers.

modules/ombi/connections/index.ts

@@ -24,7 +24,9 @@ const url = process.env.MESH_OMBI_URL ?? "http://127.0.0.1:3579";
 const apiKey = (await readIfThere(process.env.MESH_OMBI_API_KEY_FILE))?.trim() ?? process.env.MESH_OMBI_API_KEY ?? "";
 const waitSeconds = Number(process.env.MESH_OMBI_WAIT_SECONDS ?? "180");
 
-const http: Http = { fetch: (u, init) => fetch(u, init) };
+// Every call bounded: an entry ombi keeps may name a host that no longer answers, and a step that
+// hangs on it holds the apply.
+const http: Http = { fetch: (u, init) => fetch(u, { ...init, signal: AbortSignal.timeout(20_000) }) };
 
 if (!apiKey) {
   console.error("[ombi-connections] no ombi API key — ombi's own `api-key` secret has not been accepted");