Stable Asura series IDs: strip rotating build hash (#6)

Asura series slugs carry a site-wide build hash (-059befe1) that rotates on every redeploy, silently orphaning all asura bookmarks (old-hash URLs 302 to new-hash ones, so detect() yields keys that never match stored rows).

Backend:
- migrateAsuraKeys in OpenStore: one-off idempotent migration rewriting hashed asura keys to the stable hashless ID, merging collisions to newest updated_at; losers deleted before winner rewrite (PK-collision safe) — regression tests included
- poller latestChapterFrom: build hash made optional in chapter-scoping regex so latest_chapter survives redeploys

Userscript:
- stripBuildHash(/-[0-9a-f]{8}$/) applied to seriesId in both asura detect branches; URLs keep full slug (stale hashes 302)
- load-time migration rewrites cached + retry-queued asura keys to the stripped form so a queued PUT cannot resurrect an orphaned row

Docs: AGENTS.md + CLAUDE.md URL-shape notes; design spec at docs/superpowers/specs/2026-07-28-asura-stable-series-id-design.md

Verified: go test -count=1 ./... green (new rotation + collision tests), node --check green, regex verified against live asurascans.com slugs.

Deploy order: backend first (migration runs at OpenStore). Orphan rows created by not-yet-updated userscripts self-heal on next backend restart.

Reviewed-on: #6
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>

userscript/manga-bookmark.user.js

@@ -66,6 +66,18 @@
     return out;
   }
 
+  // Asura appends a site-wide build hash to every slug
+  // ("...-059befe1"); it rotates on each redeploy, so it must not be part
+  // of the series identity — old keys can never match pages after a
+  // redeploy. Only the ID strips it; seriesUrl keeps the full slug because
+  // navigation needs the current hash (stale ones 302). Must stay in sync
+  // with asuraBuildHash in backend/store.go.
+  // ponytail: a real title ending in exactly 8 hex chars would lose its
+  // last segment; none known.
+  function stripBuildHash(slug) {
+    return slug.replace(/-[0-9a-f]{8}$/, "");
+  }
+
   const asura = {
     site: "asura",
     // asuracomic.net deep links 301 to the asurascans.com *root*, dropping the
@@ -83,7 +95,7 @@
         return {
           type: "chapter",
           site: this.site,
-          seriesId: m[1],
+          seriesId: stripBuildHash(m[1]),
           title: cleanTitle(meta("og:title")),
           cover: meta("og:image") || "",
           seriesUrl: loc.origin + "/comics/" + m[1],
@@ -98,7 +110,7 @@
         return {
           type: "series",
           site: this.site,
-          seriesId: m[1],
+          seriesId: stripBuildHash(m[1]),
           title: cleanTitle(meta("og:title")),
           cover: meta("og:image") || "",
           seriesUrl: loc.origin + "/comics/" + m[1],
@@ -384,6 +396,38 @@
 
   const queue = loadQueue();
 
+  // Keys cached (or parked in the retry queue) by versions before the
+  // Asura build-hash strip still carry the hash. Align them with the
+  // server-side migration so a queued PUT cannot resurrect an orphaned
+  // row and the cache matches what the server now returns. Duplicate
+  // cache entries collapsing onto one key are left as-is — the next
+  // refresh() replaces the whole list from the already-merged server.
+  (function migrateLocalKeys() {
+    let dirty = false;
+    for (let i = 0; i < state.list.length; i++) {
+      const b = state.list[i];
+      if (b.site !== "asura" || !b.series_id) continue;
+      const id = stripBuildHash(b.series_id);
+      if (id === b.series_id) continue;
+      state.list[i] = Object.assign({}, b, { series_id: id, key: "asura:" + id });
+      dirty = true;
+    }
+    if (dirty) {
+      reindex();
+      saveCache(state.list);
+    }
+    dirty = false;
+    for (const e of queue) {
+      if (!e.key.startsWith("asura:")) continue;
+      const k = "asura:" + stripBuildHash(e.key.slice("asura:".length));
+      if (k !== e.key) {
+        e.key = k;
+        dirty = true;
+      }
+    }
+    if (dirty) saveQueue(queue);
+  })();
+
   function queueCount() {
     return queue.length;
   }