diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 60f0e9b6cc2..829a71f169d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,10 +21,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
         with:
-          fetch-depth: 50
+          fetch-depth: 1
           fetch-tags: false
           submodules: false
 
+      - name: Ensure docs-scope base commit
+        uses: ./.github/actions/ensure-base-commit
+        with:
+          base-sha: ${{ github.event_name == 'push' && github.event.before || github.event.pull_request.base.sha }}
+          fetch-ref: ${{ github.event_name == 'push' && github.ref_name || github.event.pull_request.base.ref }}
+
       - name: Detect docs-only changes
         id: check
         uses: ./.github/actions/detect-docs-changes
@@ -46,10 +52,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
         with:
-          fetch-depth: 50
+          fetch-depth: 1
           fetch-tags: false
           submodules: false
 
+      - name: Ensure changed-scope base commit
+        uses: ./.github/actions/ensure-base-commit
+        with:
+          base-sha: ${{ github.event_name == 'push' && github.event.before || github.event.pull_request.base.sha }}
+          fetch-ref: ${{ github.event_name == 'push' && github.ref_name || github.event.pull_request.base.ref }}
+
       - name: Detect changed scopes
         id: scope
         shell: bash
@@ -75,6 +87,13 @@ jobs:
         with:
           submodules: false
 
+      - name: Ensure secrets base commit (PR fast path)
+        if: github.event_name == 'pull_request'
+        uses: ./.github/actions/ensure-base-commit
+        with:
+          base-sha: ${{ github.event.pull_request.base.sha }}
+          fetch-ref: ${{ github.event.pull_request.base.ref }}
+
       - name: Setup Node environment
         uses: ./.github/actions/setup-node-env
         with: