fix(backend): strip build hash in poller chapter scoping

backend/latest_sites.go

@@ -14,7 +14,9 @@ type latestChapter struct {
 
 // asuraSlugRe pulls the series slug out of a stored series_url.
 // Shape verified live 2026-07-26: https://asurascans.com/comics/<slug>, where
-// the slug carries a trailing hash-like suffix (e.g. "-f886a8af").
+// the slug carries a trailing build-hash suffix (e.g. "-f886a8af") that
+// rotates on every site redeploy — callers must strip it (asuraBuildHash)
+// before using the slug to scope anything.
 var asuraSlugRe = regexp.MustCompile(`/comics/([^/?#]+)`)
 
 // demonicChapterRe matches the pre-redirect anchors demonic series pages link
@@ -47,9 +49,14 @@ func latestChapterFrom(site, seriesURL, body string) (latestChapter, bool) {
 		if m == nil {
 			return latestChapter{}, false
 		}
+		// Stored URLs predating a redeploy may carry a stale build hash;
+		// chapter hrefs in the fetched body carry the current one. Strip to
+		// the stable ID (same rule as migrateAsuraKeys) and make the hash
+		// optional in the pattern, so scoping survives rotations.
+		slug := asuraBuildHash.ReplaceAllString(m[1], "")
 		// Compiled per call rather than cached: this runs once per fetch, which
 		// is at most a few times a minute, and the slug varies per series.
-		re = regexp.MustCompile(`/comics/` + regexp.QuoteMeta(m[1]) + `/chapter/([0-9.]+)`)
+		re = regexp.MustCompile(`/comics/` + regexp.QuoteMeta(slug) + `(?:-[0-9a-f]{8})?/chapter/([0-9.]+)`)
 	case "demonic":
 		re = demonicChapterRe
 	default:

backend/latest_sites_test.go

@@ -57,6 +57,13 @@ func TestLatestChapterFrom(t *testing.T) {
 			site: "asura", seriesURL: asuraURL, body: asuraCrossSeriesFixture,
 			wantOK: true, wantNum: 181, wantLabel: "Chapter 181",
 		},
+		{
+			name:      "asura scoping survives a build-hash rotation",
+			site:      "asura",
+			seriesURL: "https://asurascans.com/comics/chronicles-of-the-demon-faction-059befe1",
+			body:      asuraCrossSeriesFixture,
+			wantOK:    true, wantNum: 181, wantLabel: "Chapter 181",
+		},
 		{
 			name: "asura with an unparseable series url",
 			site: "asura", seriesURL: "https://asurascans.com/", body: asuraSeriesFixture,