refactor(ci): consolidate spec compliance into main CI workflow

- Move spec-consistency job from spec-compliance.yml to ci.yml
- Move spec-compliance (cucumber tests) job to ci.yml
- Make spec-consistency a prerequisite for test matrix and cucumber tests
- Delete spec-compliance.yml
- All CI checks now in single workflow file for easier management

Author: mroderick

.github/workflows/ci.yml

@@ -48,9 +48,27 @@ jobs:
       - name: Run fallow check
         run: npx fallow dead-code
 
+  spec-consistency:
+    name: Spec Consistency
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+      - name: Check spec matches website
+        run: |
+          curl -sL \
+            https://raw.githubusercontent.com/idempot-dev/website/main/docs/specs/idempotency.feature \
+            -o /tmp/website.feature
+          tail -n +5 tests/spec/idempotency.feature > /tmp/local.feature
+          diff /tmp/local.feature /tmp/website.feature || {
+            echo "::error::Spec file diverged from website. Run: pnpm run spec:sync"
+            exit 1
+          }
+
   test:
     name: Test (Node.js ${{ matrix.node-version }})
-    needs: [lint, commitlint, fallow]
+    needs: [lint, commitlint, fallow, spec-consistency]
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -203,6 +221,24 @@ jobs:
       - name: Run Deno tests
         run: pnpm run test:deno
 
+  spec-compliance:
+    name: Spec Compliance (Cucumber)
+    needs: [spec-consistency, lint, commitlint]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
+        with:
+          node-version: 22
+      - name: Enable pnpm
+        run: corepack enable
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+      - name: Run cucumber spec tests
+        run: pnpm run test:spec
+
   validate-workflows:
     runs-on: ubuntu-latest
     permissions: