Adventure news: fix posting gates, digest counts, and section gating

- Don't post adventure beats when posting.enabled=false (PostNow ignores the flag)
- Keep the adventure channel out of the round-robin rotation so it can't steal bulletins from the digest
- no_push now retires a fact against the digest, not just the live post
- Default a missing occurred_at to now instead of the Unix epoch
- Keep protocol-relative image URLs on the guarded thumbnailer
- Make digest_hour=0 (midnight UTC) settable
- Quote the true window total in the digest, not the truncated slice
- Hide the Adventure section entirely when it's disabled

internal/web/handlers.go

@@ -160,7 +160,7 @@ func (s *Server) base(r *http.Request) pageData {
 	}
 	d := pageData{
 		SiteTitle:      s.cfg.SiteTitle,
-		Channels:       channels,
+		Channels:       s.channels,
 		Weather:        currentWeather(time.Now()),
 		AllSources:     jsForScript(srcJSON),
 		AuthEnabled:    s.auth != nil,
@@ -217,8 +217,8 @@ func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
 	}
 
 	dayStart := time.Now().Add(-24 * time.Hour).Unix()
-	stats := make([]channelStat, 0, len(channels))
-	for _, ch := range channels {
+	stats := make([]channelStat, 0, len(s.channels))
+	for _, ch := range s.channels {
 		total, _ := storage.CountClassifiedByChannel(ch.Slug)
 		lastTs := storage.GetLastPostTime(ch.Slug)
 		stat := channelStat{