diff --git a/.github/workflows/watch.yml b/.github/workflows/watch.yml
index 91c61fd789..b9af8ed0a7 100644
--- a/.github/workflows/watch.yml
+++ b/.github/workflows/watch.yml
@@ -6,17 +6,18 @@
 # parity script normalizes sitemap entries: URL pathname, trailing slash
 # stripped, "" → "/").
 #
-# On any failure the run files an issue on this repo (labeled
-# production-watch) with the captured output, and the run itself fails.
+# On any failure the run reports on this repo and the run itself fails. If an
+# issue labeled production-watch is already open, the run comments on it
+# instead of filing a duplicate (#118-#179 were one stale fixture entry
+# re-filed every 6 hours); otherwise it opens a new one.
 #
-# NOTE: downgrade the cron to weekly after 2026-08-29 (14 days
-# post-cutover) — every 6 hours is only warranted while the fiestaboard.app
-# cutover settles.
+# Runs weekly: the 6-hourly cadence was only for the fiestaboard.app cutover,
+# which settled after 2026-08-29. Use workflow_dispatch for an ad-hoc check.
 name: Production watch
 
 on:
   schedule:
-    - cron: "41 */6 * * *" # every 6 hours, off the top of the hour
+    - cron: "41 14 * * 1" # weekly, Monday 14:41 UTC, off the top of the hour
   workflow_dispatch: {}
 
 permissions:
@@ -131,6 +132,17 @@ jobs:
             --description "Filed automatically by the production watch workflow" \
             --color D93F0B 2>/dev/null || true
 
+          # De-duplicate: report on the oldest open production-watch issue
+          # if there is one, rather than filing a new issue every run.
+          EXISTING="$(gh issue list --repo "$GITHUB_REPOSITORY" \
+            --label production-watch --state open --limit 100 \
+            --json number --jq 'map(.number) | min // empty' 2>/dev/null || true)"
+          if [ -n "$EXISTING" ]; then
+            echo "Open production-watch issue #$EXISTING exists; commenting instead of filing a new one."
+            gh issue comment "$EXISTING" --repo "$GITHUB_REPOSITORY" --body-file "$BODY"
+            exit 0
+          fi
+
           if ! gh issue create --repo "$GITHUB_REPOSITORY" \
             --title "$TITLE" --label production-watch --body-file "$BODY"; then
             echo "::warning::issue creation with label failed; retrying without label"
diff --git a/tests/routes-fixture-versions.test.mjs b/tests/routes-fixture-versions.test.mjs
new file mode 100644
index 0000000000..82c8dcb048
--- /dev/null
+++ b/tests/routes-fixture-versions.test.mjs
@@ -0,0 +1,48 @@
+// Keeps tests/routes.fixture.json consistent with which docs versions a
+// deploy actually builds. Deploys only build versions.slice(0,
+// DEPLOY_VERSION_CAP) (docusaurus.config.ts); every older snapshot is served
+// as a redirect stub to the current docs. Each release snapshot pushes one
+// version off the cap, so a fixture entry that pins an old version as a
+// "page" silently goes stale — that is what filed #118–#179 (8.28 fell off
+// the cap with the 9.10 snapshot on 2026-10-03). This test fails the
+// snapshot PR instead of the production watch.
+
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { test } from "node:test";
+
+const read = (p) => readFileSync(new URL(`../${p}`, import.meta.url), "utf8");
+const versions = JSON.parse(read("versions.json"));
+const fixture = JSON.parse(read("tests/routes.fixture.json"));
+const capMatch = read("docusaurus.config.ts").match(/const DEPLOY_VERSION_CAP = (\d+);/);
+
+test("DEPLOY_VERSION_CAP is readable from docusaurus.config.ts", () => {
+  assert.ok(capMatch, "could not find `const DEPLOY_VERSION_CAP = <n>;`");
+});
+
+const built = new Set(versions.slice(0, Number(capMatch?.[1] ?? 0)));
+const known = new Set(versions);
+const versioned = fixture
+  .map((e) => ({ e, v: e.path.match(/^\/docs\/(\d+\.\d+)(?:\/|$)/)?.[1] }))
+  .filter(({ v }) => v && known.has(v));
+
+for (const { e, v } of versioned) {
+  test(`fixture ${e.path} (${e.expect}) agrees with the version cap`, () => {
+    if (built.has(v)) {
+      // Built version: either a real page or the version root → its intro.
+      if (e.expect === "redirect")
+        assert.ok(
+          e.target.startsWith(`/docs/${v}/`),
+          `${v} is built, so ${e.path} should not redirect out of /docs/${v}/ (target ${e.target})`,
+        );
+    } else {
+      assert.equal(
+        e.expect,
+        "redirect",
+        `${v} is past DEPLOY_VERSION_CAP and is no longer built — ${e.path} is a redirect stub, not a page`,
+      );
+      const rest = e.path.slice(`/docs/${v}`.length) || "/intro";
+      assert.equal(e.target, `/docs${rest}`, `${e.path} should redirect to the current docs at the same path`);
+    }
+  });
+}
diff --git a/tests/routes.fixture.json b/tests/routes.fixture.json
index 2eb73ce02e..1d56bf2e36 100644
--- a/tests/routes.fixture.json
+++ b/tests/routes.fixture.json
@@ -9,7 +9,7 @@
   { "path": "/docs/troubleshooting", "expect": "page" },
 
   { "path": "/docs/8.30/intro", "expect": "page", "fullBuildOnly": true },
-  { "path": "/docs/8.28/setup/quick-start", "expect": "page", "fullBuildOnly": true },
+  { "path": "/docs/8.28/setup/quick-start", "expect": "redirect", "target": "/docs/setup/quick-start" },
   { "path": "/docs/8.15/intro", "expect": "redirect", "target": "/docs/intro", "fullBuildOnly": true },
   { "path": "/docs/8.30", "expect": "redirect", "target": "/docs/8.30/intro", "fullBuildOnly": true },