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/reader_credential_test.go

@@ -49,7 +49,7 @@ func withBody(req *http.Request, body string) *http.Request {
 // A refused credential is refused however plausible it looks: only a hash the
 // readers table holds authenticates anything.
 func TestUnknownCredentialRejected(t *testing.T) {
-	srv := newRouter(newTestStore(t), testConfig(), nil)
+	srv := newRouter(newTestStore(t), testConfig())
 
 	rr := httptest.NewRecorder()
 	srv.ServeHTTP(rr, credRequest(http.MethodGet, "/bookmarks", readerCredential("never-registered")))
@@ -69,7 +69,7 @@ func TestUnknownCredentialRejected(t *testing.T) {
 func TestPerReaderIsolation(t *testing.T) {
 	s := newTestStore(t)
 	registerReader(t, s, "other-reader")
-	srv := newRouter(s, testConfig(), nil)
+	srv := newRouter(s, testConfig())
 
 	ownerKey := "asura:solo"
 	putBookmark(t, srv, ownerKey, store.Bookmark{
@@ -267,7 +267,7 @@ func TestRotateCredentialViaWebUI(t *testing.T) {
 	}
 	cfg := testConfig()
 	cfg.UserscriptPath = path
-	srv := newRouter(s, cfg, nil)
+	srv := newRouter(s, cfg)
 
 	oldCred := ownerCredential()
 	rr := httptest.NewRecorder()