Dashboard writes were silently GETs

Publishing a notice did nothing and said it had worked. `api()` took only
`path` and dropped the options object every caller passes, so
`api(path, {method: "POST", body: ...})` fetched the URL. The read
succeeded -- notices are publicly listable -- so the page printed
"zveřejněno" over a collection that had not changed. Switching a notice
on or off is a PATCH and went the same way.

It takes method and body now, and reports what PocketBase said rather
than a bare status, so a permissions problem cannot look like an outage.

Found because the owner tried to tell the family that the anime tab is
down -- AniList have disabled their API, and every call returns 403 with
"The AniList API has been temporarily disabled due to severe stability
issues" -- and the notice never reached anyone.

pb_public/status.html

@@ -206,10 +206,33 @@ function statusPill(s){
   return '<span class="pill no">' + esc(t) + "</span>";
 }
 
-async function api(path){
-  var r = await fetch(path, { headers: { Authorization: tok } });
+// Takes the options its callers have always passed.
+//
+// It used to accept only `path`, so every write on this page -- publishing a
+// notice, switching one off -- was quietly performed as a GET. The read
+// succeeded (the collection is publicly listable), so the page reported
+// "zveřejněno" and nothing had been written. A notice about the anime tab being
+// down never reached anyone.
+async function api(path, opts){
+  opts = opts || {};
+  var init = { method: opts.method || "GET", headers: { Authorization: tok } };
+  if (opts.body !== undefined) {
+    init.headers["Content-Type"] = "application/json";
+    init.body = JSON.stringify(opts.body);
+  }
+  var r = await fetch(path, init);
   if (r.status === 401) { logout(); throw new Error("401"); }
-  if (!r.ok) throw new Error("HTTP " + r.status);
+  if (!r.ok) {
+    // PocketBase explains itself in the body; say what it said rather than a
+    // bare status, or a permission problem looks the same as an outage.
+    var detail = "";
+    try {
+      var j = await r.json();
+      if (j && j.message) detail = ": " + j.message;
+    } catch (_) {}
+    throw new Error("HTTP " + r.status + detail);
+  }
+  if (r.status === 204) return null;
   return r.json();
 }