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/server.go

@@ -31,6 +31,10 @@ type Channel struct {
 }
 
 // channels in display order. Add a new entry here to add a section.
+//
+// This is the full catalogue, used to resolve a story's channel slug to its
+// display metadata. It is NOT the list of live sections: an entry can be gated
+// off (adventure), so route registration and the nav read s.channels instead.
 var channels = []Channel{
 	{Slug: "gaming", Title: "Gaming", Theme: "gaming", Emoji: "🎮", Blurb: "Releases, platforms, and the people making the games."},
 	{Slug: "tech", Title: "Tech", Theme: "tech", Emoji: "💻", Blurb: "Industry, products, and the wires that hold it all together."},
@@ -64,6 +68,7 @@ type Server struct {
 	pushHTTP       *http.Client                  // SSRF-guarded client for Web Push delivery; built lazily by pushClient()
 	adv            config.AdventureConfig        // gogobee adventure-news seam
 	advPost        PriorityPoster                // posts priority adventure beats to Matrix; nil = web-only
+	channels       []Channel                     // live sections: the catalogue minus anything gated off (adventure)
 
 	// Daily-rotated salt for the privacy-preserving unique-visitor estimate.
 	// Guarded by metricsMu; never persisted (see metrics.go).
@@ -102,7 +107,18 @@ func New(cfg config.WebConfig, sources []config.SourceConfig, postingEnabled boo
 			adminSubs[sub] = true
 		}
 	}
-	s := &Server{cfg: cfg, sources: infos, postingEnabled: postingEnabled, tpls: tpls, adminSubs: adminSubs, adv: adv, advPost: advPost}
+	// The adventure section only exists when it's enabled: with the seam off,
+	// there's no nav tab, no /adventure page and no /adventure feed, rather than
+	// an empty section nobody can fill.
+	live := make([]Channel, 0, len(channels))
+	for _, ch := range channels {
+		if ch.Slug == "adventure" && !adv.Enabled {
+			continue
+		}
+		live = append(live, ch)
+	}
+
+	s := &Server{cfg: cfg, sources: infos, postingEnabled: postingEnabled, tpls: tpls, adminSubs: adminSubs, adv: adv, advPost: advPost, channels: live}
 
 	// Optional OIDC sign-in (Authentik). Discovery is a network call; if the
 	// provider is unreachable at boot we log and serve anonymously rather than
@@ -150,7 +166,7 @@ func New(cfg config.WebConfig, sources []config.SourceConfig, postingEnabled boo
 	mux.HandleFunc("GET /api/related", s.handleRelated)
 	mux.HandleFunc("GET /feed.xml", func(w http.ResponseWriter, r *http.Request) { s.handleFeedXML(w, r, "") })
 	mux.HandleFunc("GET /feed.json", func(w http.ResponseWriter, r *http.Request) { s.handleFeedJSON(w, r, "") })
-	for _, ch := range channels {
+	for _, ch := range s.channels {
 		ch := ch
 		mux.HandleFunc("GET /"+ch.Slug, func(w http.ResponseWriter, r *http.Request) {
 			s.handleChannel(w, r, ch)