soulseek, extracted from the platform as a plugin

Seventh plugin out, and the first that was already dead. Soulseek had been
switched off since 2026-08-13: hono.ts had the router import and its mount
commented out, so createSidecarProxy never ran, registerProxiedPrefix was never
called, the slskd:server announcement fired into a void, and officer-slskd was
not in the ecosystem at all. The permission entry had been reduced to api: [],
which is why assertPermissionTotality was satisfied and the server booted
clean. The UI rendered perfectly and every request 404'd.

So this is a resurrection as well as a move.

The mount is now /api/soulseek, derived via mountPrefix from the appName — all
47 frontend call sites repointed from /slskd/. The credential key in
service_connections stays 'slskd': it names the daemon, not the route. Those
two strings differ on purpose and conflating them reads the wrong row.

The connection stays in core service_connections, as transmission does, so
'slskd' remains in a platform union this plugin cannot extend. Recorded in
PLUGIN.md. Unlike transmission this plugin does own a schema: favourites and
the two halves of the cached browse tree, which slskd has no concept of. Those
three tables had been dropped from the drizzle barrel, so bun db:push would
have deleted them on any server holding data.

313 palette classes converted to the semantic tone set, including a shared
PHASE_TONE the three transfer views previously each copied.

web/useSoulseekFavorites.ts

@@ -0,0 +1,47 @@
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { useClient } from 'hooks/useClient';
+
+const KEY = ['soulseek', 'favorites'] as const;
+const EMPTY: string[] = [];
+
+/**
+ * The owner's favourited Soulseek peers, backed by the officer-slskd sidecar's own `/_officer/favorites`
+ * route (slskd has no favourites API — Officer owns that data). One shared react-query cache, so every
+ * star in the workspace reflects the same state; toggling is optimistic and rolls back on failure.
+ */
+export function useSoulseekFavorites() {
+  const { get, post, delete: del } = useClient();
+  const qc = useQueryClient();
+
+  const { data } = useQuery({
+    queryKey: KEY,
+    queryFn: () => get<string[]>('/soulseek/_officer/favorites'),
+    staleTime: 60_000,
+  });
+
+  const mutation = useMutation({
+    mutationFn: ({ on, username }: { on: boolean; username: string }) =>
+      on
+        ? post('/soulseek/_officer/favorites', { username })
+        : del(`/soulseek/_officer/favorites?username=${encodeURIComponent(username)}`),
+    onMutate: async ({ on, username }) => {
+      await qc.cancelQueries({ queryKey: KEY });
+      const prev = qc.getQueryData<string[]>(KEY) ?? EMPTY;
+      const next = on ? [...prev, username].sort((a, b) => a.localeCompare(b)) : prev.filter((u) => u !== username);
+      qc.setQueryData<string[]>(KEY, next);
+      return { prev };
+    },
+    onError: (_err, _vars, ctx) => {
+      if (ctx?.prev) qc.setQueryData(KEY, ctx.prev);
+    },
+  });
+
+  const favorites = data ?? EMPTY;
+  const isFavorite = (username: string) => favorites.includes(username);
+  const toggle = (username: string) => {
+    if (!username) return;
+    mutation.mutate({ on: !isFavorite(username), username });
+  };
+
+  return { favorites, isFavorite, toggle };
+}