ci: add coverage threshold check to fail below 97% (#186)

Add a step to the test workflow that:
- Reads coveredstatements and statements from clover.xml
- Calculates coverage percentage
- Fails the build if coverage drops below 97%

---------

Co-authored-by: Claude <[email protected]>

Author: deviantintegral

.github/workflows/test.yml

@@ -49,6 +49,9 @@ jobs:
       - name: Run tests
         run: vendor/bin/phpunit --testdox --display-all-issues --coverage-clover build/logs/clover.xml
 
+      - name: Check coverage threshold
+        run: php scripts/check-coverage-threshold.php build/logs/clover.xml
+
       - name: Code Coverage Annotation
         uses: ggilder/codecoverage@47c83daaf1d5a3190cad56363baf459c59114170 # v1
         with:

scripts/check-coverage-threshold.php

@@ -0,0 +1,47 @@
+#!/usr/bin/env php
+<?php
+
+declare(strict_types=1);
+
+$cloverPath = $argv[1] ?? 'build/logs/clover.xml';
+$threshold = 97.0;
+
+if (!file_exists($cloverPath)) {
+    fwrite(STDERR, "Error: Clover XML file not found at: $cloverPath\n");
+    exit(1);
+}
+
+$xml = simplexml_load_file($cloverPath);
+if ($xml === false) {
+    fwrite(STDERR, "Error: Failed to parse clover XML file\n");
+    exit(1);
+}
+
+$metrics = $xml->project->metrics;
+if ($metrics === null) {
+    fwrite(STDERR, "Error: No project metrics found in clover XML\n");
+    exit(1);
+}
+
+$statements = (int) $metrics['statements'];
+$coveredStatements = (int) $metrics['coveredstatements'];
+
+if ($statements === 0) {
+    fwrite(STDERR, "Error: No statements found in coverage report\n");
+    exit(1);
+}
+
+$coverage = ($coveredStatements / $statements) * 100;
+
+printf("Coverage: %.3f%% (%d/%d statements)\n", $coverage, $coveredStatements, $statements);
+
+if ($coverage < $threshold) {
+    fwrite(STDERR, sprintf(
+        "::error::Coverage %.3f%% is below the required threshold of %.1f%%\n",
+        $coverage,
+        $threshold
+    ));
+    exit(1);
+}
+
+echo "Coverage meets the required threshold of {$threshold}%\n";