Add Season Check page and dashboard card: per-lane readiness (season, study, lessons, highlights, feed); v2.20.0

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

server.js

@@ -67,6 +67,7 @@ import { register as registerNuggets } from './server/routes/nuggets.js'
 import { register as registerNuggetsHostUpload } from './server/routes/nuggets-host-upload.js'
 import { register as registerNuggetsWorkflow } from './server/routes/nuggets-workflow.js'
 import { register as registerPodcastWorkflow } from './server/routes/podcast-workflow.js'
+import { register as registerSeasonCheck } from './server/season-check.js'
 import { warmFeedSnapshot } from './server/feed-release.js'
 import { preferIpv4ForSeafile } from './server/seafile-dns.js'
 import { startNuggetsSeafileWatcher } from './server/nuggets-seafile-watcher.js'
@@ -129,6 +130,7 @@ registerNuggets(app)
 registerNuggetsHostUpload(app)
 registerNuggetsWorkflow(app)
 registerPodcastWorkflow(app)
+registerSeasonCheck(app)
 registerFeed(app)
 registerQrCodes(app)
 registerBiblePassage(app)