Rip out Ollama: direct_route only, no LLM layer

Pete moves to a remote host without Ollama access. Every source must
declare a direct_route channel; the classifier, explainer, semantic
dedup, !explain summaries, feed_hint, and the recent_headlines /
classification_log tables are gone. Deterministic dedup (canonical URL,
headline_norm, per-channel cooldown) remains.

internal/storage/db.go

@@ -101,15 +101,7 @@ func runMigrations(d *sql.DB) error {
 }
 
 // RunMaintenance prunes stale data. Called periodically.
-func RunMaintenance(recentWindowHours, classificationLogDays int) {
-	recentCutoff := nowUnix() - int64(recentWindowHours*3600)
-	exec("prune recent_headlines",
-		`DELETE FROM recent_headlines WHERE seen_at < ?`, recentCutoff)
-
-	logCutoff := nowUnix() - int64(classificationLogDays*86400)
-	exec("prune classification_log",
-		`DELETE FROM classification_log WHERE logged_at < ?`, logCutoff)
-
+func RunMaintenance() {
 	// Prune old stories (30 days) and their post logs / reactions
 	storyCutoff := nowUnix() - int64(30*86400)
 	exec("prune old stories",