Discover page: refresh, harvest admin and seed reasons; docs (BL-0051)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server.js

@@ -315,7 +315,11 @@ try {
   if (harvest?.status === 'running') discoveryStore.patch({ harvest: { ...harvest, status: 'interrupted', finishedAt: new Date().toISOString() } });
 } catch (error) { console.error('[discovery]', error.message); }
 const harvester = new Harvester({ cache: harvestCache, client: createAniListClient(), store: discoveryStore,
-  targetsFor: harvestTargets, onDone: job => rescore(job.kind === 'user' ? { onlyUser: job.user } : {}) });
+  targetsFor: harvestTargets, onDone: async job => {
+    // A failed follow-up rescore must reach the admin panel (lastError), not only the log.
+    try { await rescore(job.kind === 'user' ? { onlyUser: job.user } : {}); }
+    catch (error) { discoveryError = `Re-scoring after harvest ${job.id} failed: ${String(error.message || error)}`.slice(0, 300); throw error; }
+  } });
 function requestHarvest(args) {
   readDiscovery(); // A corrupt store fails closed before any AniList call.
   try { return harvester.request(args); }