(test): merge coverage from parallel test jobs

Run unit and integration tests in parallel with pcov coverage, then
merge clover reports in a coverage gate job. Enforces 80% minimum
and max 1% drop vs baseline on PRs. Remove separate integration
workflow since it's now a job in tests.yml.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: abnegate

.github/workflows/integration.yml

@@ -25,30 +25,17 @@ jobs:
         run: composer install --prefer-dist --no-progress
 
       - name: Run tests with coverage
-        run: ./vendor/bin/phpunit --testsuite Unit --coverage-clover=coverage/clover.xml --coverage-text | tee coverage/summary.txt
+        run: ./vendor/bin/phpunit --testsuite Unit --coverage-clover=coverage/unit.xml
 
-      - name: Check coverage threshold
-        run: |
-          LINE_PCT=$(grep -oP 'Lines:\s+\K[\d.]+' coverage/summary.txt | head -1)
-          echo "Line coverage: ${LINE_PCT}%"
-          if [ "$(echo "$LINE_PCT < 80" | bc -l)" -eq 1 ]; then
-            echo "::error::Coverage ${LINE_PCT}% is below 80% minimum"
-            exit 1
-          fi
-
-      - name: Upload coverage artifact
-        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+      - name: Upload coverage
         uses: actions/upload-artifact@v4
         with:
-          name: coverage-baseline
-          path: coverage/clover.xml
-          retention-days: 90
+          name: coverage-unit
+          path: coverage/unit.xml
 
-  coverage-diff:
-    name: Coverage Diff
+  integration:
+    name: Integration Tests
     runs-on: ubuntu-latest
-    if: github.event_name == 'pull_request'
-    needs: unit
 
     steps:
       - name: Checkout
@@ -64,10 +51,76 @@ jobs:
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress
 
-      - name: Generate PR coverage
-        run: ./vendor/bin/phpunit --testsuite Unit --coverage-clover=coverage/clover.xml --coverage-text | tee coverage/summary.txt
+      - name: Run tests with coverage
+        run: ./vendor/bin/phpunit --testsuite Integration --coverage-clover=coverage/integration.xml
+
+      - name: Upload coverage
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-integration
+          path: coverage/integration.xml
+
+  coverage:
+    name: Coverage Check
+    runs-on: ubuntu-latest
+    needs: [unit, integration]
+
+    steps:
+      - name: Download unit coverage
+        uses: actions/download-artifact@v4
+        with:
+          name: coverage-unit
+          path: coverage
+
+      - name: Download integration coverage
+        uses: actions/download-artifact@v4
+        with:
+          name: coverage-integration
+          path: coverage
+
+      - name: Merge and check coverage
+        run: |
+          merge_clover() {
+            local total_stmts=0 covered_stmts=0
+            for f in "$@"; do
+              [ -f "$f" ] || continue
+              s=$(grep -oP 'statements="\K\d+' "$f" | paste -sd+ | bc)
+              c=$(grep -oP 'coveredstatements="\K\d+' "$f" | paste -sd+ | bc)
+              total_stmts=$((total_stmts + s))
+              covered_stmts=$((covered_stmts + c))
+            done
+            echo "$covered_stmts $total_stmts"
+          }
+
+          read COVERED TOTAL <<< $(merge_clover coverage/unit.xml coverage/integration.xml)
+          PCT=$(echo "scale=2; $COVERED * 100 / $TOTAL" | bc)
+          echo "Coverage: ${PCT}% ($COVERED / $TOTAL statements)"
+
+          if [ "$(echo "$PCT < 80" | bc -l)" -eq 1 ]; then
+            echo "::error::Coverage ${PCT}% is below 80% minimum"
+            exit 1
+          fi
 
-      - name: Download baseline coverage
+      - name: Upload merged baseline
+        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+        run: |
+          echo "$COVERED $TOTAL" > coverage/baseline.txt
+        env:
+          COVERED: ${{ env.COVERED }}
+          TOTAL: ${{ env.TOTAL }}
+
+      - name: Save baseline artifact
+        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-baseline
+          path: |
+            coverage/unit.xml
+            coverage/integration.xml
+          retention-days: 90
+
+      - name: Download baseline (PR only)
+        if: github.event_name == 'pull_request'
         uses: dawidd6/action-download-artifact@v6
         with:
           name: coverage-baseline
@@ -76,25 +129,36 @@ jobs:
           workflow: tests.yml
           if_no_artifact_found: warn
 
-      - name: Compare coverage
+      - name: Check coverage diff (PR only)
+        if: github.event_name == 'pull_request'
         run: |
-          PR_PCT=$(grep -oP 'Lines:\s+\K[\d.]+' coverage/summary.txt | head -1)
-          echo "PR coverage: ${PR_PCT}%"
-
-          if [ ! -f coverage/baseline/clover.xml ]; then
+          if [ ! -f coverage/baseline/unit.xml ]; then
             echo "No baseline found, skipping diff check"
             exit 0
           fi
 
-          BASE_STATEMENTS=$(grep -oP 'statements="\K\d+' coverage/baseline/clover.xml | paste -sd+ | bc)
-          BASE_COVERED=$(grep -oP 'coveredstatements="\K\d+' coverage/baseline/clover.xml | paste -sd+ | bc)
-          BASE_PCT=$(echo "scale=2; $BASE_COVERED * 100 / $BASE_STATEMENTS" | bc)
+          merge_clover() {
+            local total_stmts=0 covered_stmts=0
+            for f in "$@"; do
+              [ -f "$f" ] || continue
+              s=$(grep -oP 'statements="\K\d+' "$f" | paste -sd+ | bc)
+              c=$(grep -oP 'coveredstatements="\K\d+' "$f" | paste -sd+ | bc)
+              total_stmts=$((total_stmts + s))
+              covered_stmts=$((covered_stmts + c))
+            done
+            echo "$covered_stmts $total_stmts"
+          }
+
+          read BASE_COV BASE_TOTAL <<< $(merge_clover coverage/baseline/unit.xml coverage/baseline/integration.xml)
+          BASE_PCT=$(echo "scale=2; $BASE_COV * 100 / $BASE_TOTAL" | bc)
+
+          read PR_COV PR_TOTAL <<< $(merge_clover coverage/unit.xml coverage/integration.xml)
+          PR_PCT=$(echo "scale=2; $PR_COV * 100 / $PR_TOTAL" | bc)
 
-          echo "Baseline coverage: ${BASE_PCT}%"
           DIFF=$(echo "$PR_PCT - $BASE_PCT" | bc -l)
-          echo "Delta: ${DIFF}%"
+          echo "Baseline: ${BASE_PCT}% → PR: ${PR_PCT}% (${DIFF}%)"
 
           if [ "$(echo "$DIFF < -1" | bc -l)" -eq 1 ]; then
-            echo "::error::Coverage dropped ${DIFF}% (baseline ${BASE_PCT}% → PR ${PR_PCT}%). Maximum allowed drop is 1%."
+            echo "::error::Coverage dropped ${DIFF}% (max allowed: -1%)"
             exit 1
           fi