ci(acceptance): emit a shadow release-acceptance report next to release-green (#13701)

Adds a shadow release-acceptance report alongside release-green: an inventory/reduce/oracle pipeline under `scripts/quality/release-acceptance/` with a JSON schema, fixtures and a workflow that uploads the report as an artifact.

Contained by design, which is why it merges as-is: it runs only on push to `release/v*` and on manual dispatch (never on pull requests), the step is `continue-on-error`, `permissions: contents: read`, `persist-credentials: false`, and it consumes no secrets. Nothing in the product changes; the report is advisory until we decide to promote it.

Validated as a combined board first (this PR merged with the 11 siblings of the same batch on the release tip): eslint on every changed file with the suppressions file, typecheck:core, check:open-sse-typecheck, complexity, cognitive-complexity, changelog-integrity, i18n new-key coverage, docs-sync, migration-numbering, provider-consistency and a duplicate-identifier audit all green, plus 275 passing / 0 failing focused node:test cases across the 28 test files the batch touches. Then re-validated alone on the fresh tip before this merge: conflicts re-resolved, file sizes rebaselined for this PR's own growth, eslint and this PR's focused tests re-run.

Thanks @HouMinXi!

.github/workflows/release-acceptance.yml

@@ -0,0 +1,42 @@
+name: Release acceptance
+
+on:
+  push:
+    branches: ["release/v*"]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: release-acceptance-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  acceptance:
+    name: Release acceptance
+    if: github.event_name != 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@v5
+        with:
+          node-version: "22"
+          cache: npm
+      - run: npm ci
+      - name: Emit shadow acceptance report
+        run: |
+          node scripts/quality/validate-release-acceptance.mjs \
+            --plan tests/fixtures/release-acceptance/plan-lint.json \
+            --manifests tests/fixtures/release-acceptance/shadow-manifests \
+            --out release-acceptance-report.json
+        continue-on-error: true
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: release-acceptance-report
+          path: release-acceptance-report.json
+          if-no-files-found: ignore
+          retention-days: 30