feat(web,latest): pause and resume one Site's Lane with a mandatory expiry (#147)

Two owner-gated POST routes write the durable poll_lanes pause stamp the
poller's top-of-pass gate already reads: /admin/lanes/{site}/pause validates
the duration against the fixed 1h/6h/24h allow-list and the Site against the
registry, and /admin/lanes/{site}/resume zeroes the stamp. Both cap the form
body like the API path, answer with the freshly rendered Lanes block, and
never command the poller — the pause is a fact about the Site, so it
survives a restart. The Lanes page's c-ctrl slot now carries the pausebar:
Resume while paused, the duration select plus Pause while running, with the
paused phrase read from the live poll_lanes stamp so a press renders as
paused with no pass having run. Tests cover the round trips, rejections,
body caps, the pause-before-refusal ordering, fresh-poller survival, resume
restoring the full queue, and acquisition being unaffected.

backend/internal/latest/acquire_test.go

@@ -135,6 +135,33 @@ func TestAcquireFillsChapterAndCoverFromOneFetch(t *testing.T) {
 	}
 }
 
+// A pause governs the Lane only: a Reader's first bookmark of a Series on a
+// paused Site still reads the page, because acquisition is the creation-time
+// fetch, not the poll queue (issue #147).
+func TestAcquireIgnoresLanePause(t *testing.T) {
+	s, _ := newTestStore(t)
+	if err := s.PauseLane("asura", time.Now().Add(6*time.Hour).UnixMilli()); err != nil {
+		t.Fatalf("PauseLane: %v", err)
+	}
+	page := &fakeFetcher{body: asuraSeriesAndCoverFixture, status: 200}
+	covers := &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/jpeg"}
+	acq := newAcquirer(s, page, covers)
+
+	bookmarkNewSeries(t, s, acquireSeriesURL)
+	acq.Wait()
+
+	if got := page.callCount(); got != 1 {
+		t.Fatalf("series page fetches on a paused Site = %d, want 1", got)
+	}
+	if got := covers.callCount(); got != 1 {
+		t.Fatalf("cover fetches = %d, want 1", got)
+	}
+	got := readBookmark(t, s, acquireKey)
+	if got.LatestChapterNum == nil || *got.LatestChapterNum != 181 {
+		t.Fatalf("LatestChapterNum = %v, want 181", got.LatestChapterNum)
+	}
+}
+
 // A Series that already exists is not re-acquired: no fetch, and the Cover it
 // already has is left alone.
 func TestAcquireSkipsAnExistingSeries(t *testing.T) {