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/api_test.go

@@ -48,7 +48,7 @@ func TestMain(m *testing.M) { os.Exit(pgtest.Main(m)) }
 
 func newTestServer(t *testing.T) http.Handler {
 	t.Helper()
-	return newRouter(newTestStore(t), testConfig(), nil)
+	return newRouter(newTestStore(t), testConfig())
 }
 
 func newTestStore(t *testing.T) *store.Store {
@@ -599,7 +599,7 @@ func TestLoadConfigDiscord(t *testing.T) {
 // cooldown and the poller would re-fetch that series on every single tick.
 func TestPutDoesNotClobberLatestCheckedAt(t *testing.T) {
 	s := newTestStore(t)
-	srv := newRouter(s, testConfig(), nil)
+	srv := newRouter(s, testConfig())
 
 	seedForCheck(t, s, "asura:x", "https://asurascans.com/comics/x", 777)
 
@@ -627,7 +627,7 @@ func TestPutDoesNotClobberLatestCheckedAt(t *testing.T) {
 // series stops being due the moment the PUT lands.
 func TestPutRecordsASighting(t *testing.T) {
 	s := newTestStore(t)
-	srv := newRouter(s, testConfig(), nil)
+	srv := newRouter(s, testConfig())
 
 	now := time.Now().UnixMilli()
 	hour := time.Hour.Milliseconds()
@@ -677,7 +677,7 @@ func TestUserscriptServedWithWebUIDisabled(t *testing.T) {
 
 	rr := httptest.NewRecorder()
 	req := httptest.NewRequest(http.MethodGet, "/u/"+ownerCredential()+"/manga-bookmark.user.js", nil)
-	newRouter(s, cfg, nil).ServeHTTP(rr, req)
+	newRouter(s, cfg).ServeHTTP(rr, req)
 	if rr.Code != http.StatusOK {
 		t.Fatalf("status = %d, want 200", rr.Code)
 	}
@@ -699,7 +699,7 @@ func TestNovelUserscriptServed(t *testing.T) {
 
 	cfg := testConfig()
 	cfg.NovelUserscriptPath = novelPath
-	srv := newRouter(s, cfg, nil)
+	srv := newRouter(s, cfg)
 
 	rr := httptest.NewRecorder()
 	srv.ServeHTTP(rr, httptest.NewRequest(http.MethodGet,