feat: show episode info on download and history cards

- Add includeEpisode:true to Sonarr queue and history API requests
  in both the poller and historyFetcher
- Add extractEpisode() / gatherEpisodes() helpers in dashboard.js
  and history.js to build a sorted, deduplicated episodes array
  covering all records matching a download title (handles multi-
  episode packs and series packs)
- Replace episodeInfo: sonarrMatch with episodes: gatherEpisodes()
  across all 8 assignment sites in dashboard.js
- Add episodes field to /api/history/recent response items
- Frontend: formatEpisodeInfo() renders S01E05 for single episodes
  or 'Multiple episodes' with hover tooltip listing all for packs
- CSS: .episode-info and .multi-episode tooltip styles
- ARCHITECTURE.md: update polling table and download/history schemas

server/utils/poller.js

@@ -71,7 +71,7 @@ async function pollAllServices() {
       timed('Sonarr Queue', () => Promise.all(sonarrInstances.map(inst =>
         axios.get(`${inst.url}/api/v3/queue`, {
           headers: { 'X-Api-Key': inst.apiKey },
-          params: { includeSeries: true }
+          params: { includeSeries: true, includeEpisode: true }
         }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
           console.error(`[Poller] Sonarr ${inst.id} queue error:`, err.message);
           return { instance: inst.id, data: { records: [] } };
@@ -80,7 +80,7 @@ async function pollAllServices() {
       timed('Sonarr History', () => Promise.all(sonarrInstances.map(inst =>
         axios.get(`${inst.url}/api/v3/history`, {
           headers: { 'X-Api-Key': inst.apiKey },
-          params: { pageSize: 10 }
+          params: { pageSize: 10, includeEpisode: true }
         }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
           console.error(`[Poller] Sonarr ${inst.id} history error:`, err.message);
           return { instance: inst.id, data: { records: [] } };