feat(web): read admin lanes from the durable pass log, not a poller snapshot (#145)

The Lanes page now projects store.LatestLanePasses and the owner-window
outcomes (store.LanePassOutcomes) into per-Site rows instead of reading an
in-memory Poller snapshot, so a deploy answers the instant the store is up.
Browser configuration is a config fact and reachability is derived from
recent browser-Site passes inside latest.RefuseBackoff.

This atomically deletes the in-memory path in the same commit that makes the
page read the DB: latest/status.go (LaneState, Status, LaneStatus,
recordLaneState) and the web.LaneReporter seam plus fakeLanes are gone, and
latest.refuseBackoff is renamed latest.RefuseBackoff at every callsite.
ownerWindow (#142) is referenced, never declared (contract C2)

backend/main.go

@@ -54,6 +54,11 @@ type Config struct {
 	// /u/{token}/novel-bookmark.user.js. Same bindmount, second script: the
 	// two libraries are separate installs.
 	NovelUserscriptPath string
+	// BrowserWSURL is the CDP websocket the poller's browser Sites read
+	// through. Set means a browser sidecar is configured in this deployment —
+	// the Lanes page reports the fact and derives reachability from the pass
+	// log rather than asking the poller (issue #145).
+	BrowserWSURL string
 	// LatestPoll configures the background latest-chapter fetcher.
 	LatestPoll LatestPoll
 }
@@ -108,6 +113,7 @@ func loadConfig() Config {
 		OwnerDiscordID:      os.Getenv("OWNER_DISCORD_ID"),
 		UserscriptPath:      envOr("USERSCRIPT_PATH", "/userscript/manga-bookmark.user.js"),
 		NovelUserscriptPath: envOr("NOVEL_USERSCRIPT_PATH", "/userscript/novel-bookmark.user.js"),
+		BrowserWSURL:        os.Getenv("BROWSER_WS_URL"),
 		LatestPoll:          loadLatestPoll(),
 	}
 	c.Discord = web.DiscordConfig{
@@ -130,9 +136,10 @@ func loadConfig() Config {
 // preflight OPTIONS short-circuits before auth; /bookmarks* is auth-protected,
 // /healthz is public.
 //
-// lanes may be nil — polling disabled, or its client could not be built. The
-// admin page reports that rather than pretending Lanes exist.
-func newRouter(s *store.Store, cfg Config, lanes web.LaneReporter) http.Handler {
+// The web layer learns the deployment's poller and browser config from cfg —
+// nothing of the running poller is wired through here; the Lanes page reads
+// the database (issue #145).
+func newRouter(s *store.Store, cfg Config) http.Handler {
 	mux := http.NewServeMux()
 	h := &api.Handler{Store: s}
 	mux.HandleFunc("GET /healthz", api.Healthz)
@@ -161,9 +168,12 @@ func newRouter(s *store.Store, cfg Config, lanes web.LaneReporter) http.Handler
 	mux.Handle("/bookmarks/", auth)
 
 	// The browser UI is always registered; signing in is Discord OAuth, so
-	// there is no password to forget and no gate to leave unset.
+	// there is no password to forget and no gate to leave unset. The poller
+	// and browser facts are config, not the poller's: the Lanes page reads
+	// the pass log and reports the deployment as configured.
 	wh, err := web.New(s, cfg.Discord, []byte(cfg.TokenKey),
-		cfg.UserscriptPath, cfg.NovelUserscriptPath, lanes)
+		cfg.UserscriptPath, cfg.NovelUserscriptPath,
+		cfg.LatestPoll.Enabled, strings.TrimSpace(cfg.BrowserWSURL) != "")
 	if err != nil {
 		log.Fatalf("web handler: %v", err)
 	}
@@ -241,7 +251,7 @@ func main() {
 	var browser latest.Fetcher
 	pollCtx, stopPoll := context.WithCancel(context.Background())
 	defer stopPoll()
-	if ws := strings.TrimSpace(os.Getenv("BROWSER_WS_URL")); ws != "" {
+	if ws := strings.TrimSpace(cfg.BrowserWSURL); ws != "" {
 		bf, err := latest.NewBrowserFetcher(ws)
 		if err != nil {
 			log.Printf("browser fetcher disabled: %v", err)
@@ -278,17 +288,14 @@ func main() {
 		}
 		s.OnSeriesCreated = acq.Acquire
 	}
-	// A nil *Poller must not become a non-nil interface holding a nil pointer:
-	// the admin page tests the reporter for nil to decide whether anything is
-	// polling at all.
-	var lanes web.LaneReporter
-	if poller := startLatestPoller(pollCtx, s, cfg.LatestPoll, browser); poller != nil {
-		lanes = poller
-	}
+	// The poller's only connection to the web layer is the database now: it is
+	// started for its own sake, and the Lanes page reads the pass rows it
+	// records (issue #145).
+	startLatestPoller(pollCtx, s, cfg.LatestPoll, browser)
 
 	srv := &http.Server{
 		Addr:              ":" + cfg.Port,
-		Handler:           newRouter(s, cfg, lanes),
+		Handler:           newRouter(s, cfg),
 		ReadHeaderTimeout: 10 * time.Second,
 	}