fix(notes): anchor archive seals to prior Git state

.github/workflows/ci.yml

@@ -37,8 +37,10 @@ jobs:
     env:
       DSH_GATE_CONCURRENCY: '8'
     steps:
+      # The archive gate reads the PR base manifest from the synthetic merge commit's first parent.
       - uses: actions/checkout@v6
         with:
+          fetch-depth: 2
           persist-credentials: false
 
       # Pull requests consume the default-branch cache but do not put cache
@@ -60,6 +62,8 @@ jobs:
           pnpm install --frozen-lockfile
 
       - name: Run static gates
+        env:
+          DSH_ARCHIVE_BASE_REF: ${{ github.event.pull_request.base.sha }}
         run: pnpm run check:ci:static
 
       - name: Pack built tree
@@ -323,6 +327,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
+        with:
+          fetch-depth: 2
 
       - uses: actions/setup-node@v6
         with:
@@ -357,6 +363,7 @@ jobs:
 
       - name: Run complete unsharded primary Node CI serially
         env:
+          DSH_ARCHIVE_BASE_REF: ${{ github.event.before }}
           DSH_COVERAGE_MAX_WORKERS: '1'
           DSH_E2E_MAX_WORKERS: '1'
           DSH_ESLINT_CACHE: '1'