fix(web): surface a toast on failed mutations (#14)

Several client mutations either ignored a non-ok response (silent no-op) or
toasted success unconditionally even when the request failed. Sweep them so every
mutation gives feedback:

- artists: toggle auto-monitor, unfollow → error toast on failure.
- discography + wanted: toggle monitor / search-now → success or error toast.
- discover suggestion follow/want/dismiss → error toast (was toasting success
  even on failure).
- The Floor: queue request + retry → error toast on failure.
- artist-modal + preview follow/want, Last.fm want → error toast on failure
  (closes the deferred "want() shows no toast on non-ok" item).

web 153 tests, tsc + build clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/app/_ui/artist-modal.tsx

@@ -102,6 +102,8 @@ export function ArtistModal({
     if (res.ok || res.status === 409) {
       setFollowed(true);
       toast(`Following ${name}`);
+    } else {
+      toast(`Couldn't follow ${name}`);
     }
   }
 
@@ -122,6 +124,8 @@ export function ArtistModal({
     if (res.ok) {
       setWanted((s) => new Set(s).add(r.rgMbid));
       toast(`Added ${r.album}`);
+    } else {
+      toast(`Couldn't add ${r.album}`);
     }
   }
 

web/src/app/artists/[id]/discography-client.tsx

@@ -4,6 +4,7 @@ import { useEffect, useMemo, useState } from "react";
 import { PageHead } from "../../_ui/page-head";
 import { CoverArt } from "../../_ui/cover-art";
 import { AlbumModal } from "../../_ui/album-modal";
+import { toast } from "../../_ui/toast";
 import { categoryOf, TAB_ORDER, type Category } from "../../_ui/categories";
 
 type Release = {
@@ -39,15 +40,17 @@ export function DiscographyClient({ id }: { id: string }) {
   }, [id]);
 
   async function toggleMonitor(r: Release) {
-    await fetch(`/api/releases/${r.id}`, {
+    const res = await fetch(`/api/releases/${r.id}`, {
       method: "PATCH",
       headers: { "content-type": "application/json" },
       body: JSON.stringify({ monitored: !r.monitored }),
-    });
+    }).catch(() => null);
+    if (!res?.ok) toast(`Couldn't update ${r.album}`);
     refresh();
   }
   async function searchNow(r: Release) {
-    await fetch(`/api/releases/${r.id}/search`, { method: "POST" });
+    const res = await fetch(`/api/releases/${r.id}/search`, { method: "POST" }).catch(() => null);
+    toast(res?.ok ? `Searching for ${r.album}` : `Couldn't search for ${r.album}`);
     refresh();
   }
 

web/src/app/artists/artists-client.tsx

@@ -95,16 +95,18 @@ export function ArtistsClient() {
   }
 
   async function toggleAuto(a: Artist) {
-    await fetch(`/api/artists/${a.id}`, {
+    const res = await fetch(`/api/artists/${a.id}`, {
       method: "PATCH",
       headers: { "content-type": "application/json" },
       body: JSON.stringify({ autoMonitorFuture: !a.autoMonitorFuture }),
-    });
+    }).catch(() => null);
+    if (!res?.ok) toast(`Couldn't update ${a.name}`);
     refresh();
   }
 
   async function unfollow(a: Artist) {
-    await fetch(`/api/artists/${a.id}`, { method: "DELETE" });
+    const res = await fetch(`/api/artists/${a.id}`, { method: "DELETE" }).catch(() => null);
+    if (!res?.ok) toast(`Couldn't unfollow ${a.name}`);
     refresh();
   }
 

web/src/app/discover/artist/[mbid]/preview-client.tsx

@@ -55,6 +55,8 @@ export function PreviewClient({ mbid, initialName }: { mbid: string; initialName
     if (res.ok || res.status === 409) {
       setFollowed(true);
       toast(`Following ${name}`);
+    } else {
+      toast(`Couldn't follow ${name}`);
     }
   }
 
@@ -75,6 +77,8 @@ export function PreviewClient({ mbid, initialName }: { mbid: string; initialName
     if (res.ok) {
       setWanted((s) => new Set(s).add(r.rgMbid));
       toast(`Added ${r.album}`);
+    } else {
+      toast(`Couldn't add ${r.album}`);
     }
   }
 

web/src/app/discover/discover-client.tsx

@@ -103,11 +103,15 @@ export function DiscoverClient() {
   }
 
   async function act(id: string, action: "follow" | "want" | "dismiss") {
-    await fetch(`/api/discover/${id}`, {
+    const res = await fetch(`/api/discover/${id}`, {
       method: "POST",
       headers: { "content-type": "application/json" },
       body: JSON.stringify({ action }),
-    });
+    }).catch(() => null);
+    if (!res?.ok) {
+      toast(`Couldn't ${action}`);
+      return;
+    }
     toast(action === "follow" ? "Following" : action === "want" ? "Added to wanted" : "Dismissed");
     loadFeed();
   }

web/src/app/lastfm/lastfm-client.tsx

@@ -174,6 +174,8 @@ export function LastfmClient() {
       toast(`Wanted ${match.title}`);
       setWantedSet((s) => new Set(s).add(match.rgMbid));
       setAlbumTarget(null);
+    } else {
+      toast(`Couldn't add ${match.title}`);
     }
   }
 

web/src/app/queue.tsx

@@ -76,22 +76,28 @@ export function Queue() {
   }, []);
 
   async function retry(id: string) {
-    const res = await fetch(`/api/requests/${id}/retry`, { method: "POST" });
+    const res = await fetch(`/api/requests/${id}/retry`, { method: "POST" }).catch(() => null);
-    if (res.ok) {
+    if (!res?.ok) {
-      toast("Retrying…");
+      toast("Couldn't retry");
-      refresh();
+      return;
     }
+    toast("Retrying…");
+    refresh();
   }
 
   async function submit(e: React.FormEvent) {
     e.preventDefault();
     if (!artist.trim() || !album.trim()) return;
     const label = album.trim();
-    await fetch("/api/requests", {
+    const res = await fetch("/api/requests", {
       method: "POST",
       headers: { "content-type": "application/json" },
       body: JSON.stringify({ artist, album }),
-    });
+    }).catch(() => null);
+    if (!res?.ok) {
+      toast(`Couldn't queue ${label}`);
+      return;
+    }
     toast(`Queued ${label}`);
     setArtist("");
     setAlbum("");

web/src/app/wanted/wanted-client.tsx

@@ -60,8 +60,8 @@ export function WantedClient() {
   }
 
   async function searchNow(w: Wanted) {
-    await fetch(`/api/releases/${w.id}/search`, { method: "POST" });
+    const res = await fetch(`/api/releases/${w.id}/search`, { method: "POST" }).catch(() => null);
-    toast(`Searching for ${w.album}`);
+    toast(res?.ok ? `Searching for ${w.album}` : `Couldn't search for ${w.album}`);
     refresh();
   }