diff --git a/.claude/release-process.md b/.claude/release-process.md
index 68404812..256d530c 100644
--- a/.claude/release-process.md
+++ b/.claude/release-process.md
@@ -222,7 +222,7 @@ Runtime env vars for bin scripts (not stored as secrets — passed at the comman
 
 **Tests fail before release**
 - Fix the failing tests. They must pass before tagging.
-- Run locally: `/opt/homebrew/Cellar/php/8.5.1_2/bin/php vendor/bin/pest --parallel`
+- Run locally: `php vendor/bin/pest --parallel` (ensure PHP 8.5+ is on your PATH, or set `PHP_BIN` env var)
 
 **`composer update` fails locally**
 - Always run from the repo root (not inside a package directory)
diff --git a/bin/release.sh b/bin/release.sh
index 77751dd0..66522047 100755
--- a/bin/release.sh
+++ b/bin/release.sh
@@ -32,10 +32,7 @@ if git rev-parse "$TAG" >/dev/null 2>&1; then
 fi
 
 # Find PHP 8.5+ binary
-PHP_BIN="/opt/homebrew/Cellar/php/8.5.1_2/bin/php"
-if [[ ! -x "$PHP_BIN" ]]; then
-    PHP_BIN="php"
-fi
+PHP_BIN="${PHP_BIN:-php}"
 
 PHP_VERSION=$("$PHP_BIN" -r 'echo PHP_MAJOR_VERSION . "." . PHP_MINOR_VERSION;')
 if [[ "$PHP_VERSION" != "8.5" ]]; then
diff --git a/packages/cli/bin/marko b/packages/cli/bin/marko
index 4905d0f7..261320e3 100755
--- a/packages/cli/bin/marko
+++ b/packages/cli/bin/marko
@@ -21,11 +21,15 @@ use Marko\Cli\CliKernel;
 use Marko\Cli\ProjectFinder;
 
 try {
-    $kernel = new CliKernel(
-        projectFinder: new ProjectFinder(),
-    );
-    $exitCode = $kernel->run($argv);
-    exit($exitCode);
+    $projectFinder = new ProjectFinder();
+
+    if (($projectRoot = $projectFinder->find()) !== null) {
+        require_once "{$projectRoot}/vendor/autoload.php";
+    }
+
+    exit((new CliKernel(
+        projectFinder: $projectFinder,
+    ))->run($argv));
 } catch (Throwable $e) {
     fwrite(STDERR, "Error: " . $e->getMessage() . PHP_EOL);
     exit(1);
diff --git a/packages/cli/tests/BinMarkoTest.php b/packages/cli/tests/BinMarkoTest.php
index 1ad5c58c..28e52ce2 100644
--- a/packages/cli/tests/BinMarkoTest.php
+++ b/packages/cli/tests/BinMarkoTest.php
@@ -24,21 +24,30 @@
     $content = file_get_contents($binMarkoPath);
 
     expect($content)->toContain('use Marko\Cli\CliKernel')
-        ->and($content)->toContain('new CliKernel');
+        ->and($content)->toContain('new CliKernel')
+        ->and($content)->toContain('projectFinder: $projectFinder');
 });
 
 it('passes argv to kernel run method', function () use ($binMarkoPath) {
     $content = file_get_contents($binMarkoPath);
 
-    expect($content)->toContain('$kernel->run($argv)');
+    expect($content)->toContain('->run($argv)');
 });
 
 it('exits with code returned from kernel', function () use ($binMarkoPath) {
     $content = file_get_contents($binMarkoPath);
 
-    // Should capture exit code and use it
-    expect($content)->toContain('$exitCode')
-        ->and($content)->toContain('exit($exitCode)');
+    expect($content)->toContain('exit((new CliKernel(')
+        ->and($content)->toContain('))->run($argv));');
+});
+
+it('loads the project autoloader when a project root is found', function () use ($binMarkoPath) {
+    $content = file_get_contents($binMarkoPath);
+
+    expect($content)->toContain('use Marko\Cli\ProjectFinder')
+        ->and($content)->toContain('$projectFinder = new ProjectFinder()')
+        ->and($content)->toContain('$projectFinder->find()')
+        ->and($content)->toContain('require_once "{$projectRoot}/vendor/autoload.php"');
 });
 
 it('handles uncaught exceptions gracefully', function () use ($binMarkoPath) {
diff --git a/packages/dev-server/tests/Command/DevDownCommandTest.php b/packages/dev-server/tests/Command/DevDownCommandTest.php
index 77e8c8bf..36c32ef3 100644
--- a/packages/dev-server/tests/Command/DevDownCommandTest.php
+++ b/packages/dev-server/tests/Command/DevDownCommandTest.php
@@ -304,10 +304,22 @@ function createDevDownCommand(array $config = [], ?string $tmpDir = null): array
 
     usleep(100000); // let signals propagate
 
-    // Both parent and child should be dead — process group killed
-    expect($pidFile->isProcessGroupRunning($parentPid))->toBeFalse();
-
     proc_close($proc);
+
+    $groupRunning = true;
+    for ($i = 0; $i < 10; $i++) {
+        $groupRunning = $pidFile->isProcessGroupRunning($parentPid);
+        if ($groupRunning === false) {
+            break;
+        }
+
+        usleep(50000);
+    }
+
+    // Reap the parent process before asserting so zombie cleanup does not
+    // make the process group appear alive briefly on Linux.
+    expect($groupRunning)->toBeFalse();
+
     devDownRemoveDir($tmpDir);
 });
 
diff --git a/tests/IntegrationVerificationTest.php b/tests/IntegrationVerificationTest.php
index fbfa9427..3f8962e8 100644
--- a/tests/IntegrationVerificationTest.php
+++ b/tests/IntegrationVerificationTest.php
@@ -43,15 +43,46 @@ function () use ($packagesRoot, $packages): void {
 it(
     'removes composer.lock and vendor/ before running composer update to ensure clean resolution',
     function () use ($root): void {
-        $php = '/opt/homebrew/Cellar/php/8.5.1_2/bin/php';
+        $php = PHP_BINARY;
         $resultFile = tempnam(sys_get_temp_dir(), 'marko_result_');
+        $isolatedRoot = sys_get_temp_dir() . '/marko-clean-install-' . uniqid();
     
         $script = <<<'SCRIPT'
 <?php
-[$root, $resultFile] = [$argv[1], $argv[2]];
+[$root, $resultFile, $php, $isolatedRoot] = [$argv[1], $argv[2], $argv[3], $argv[4]];
 
 $results = [];
 
+function copyTree(string $source, string $destination): void
+{
+    if (is_link($source)) {
+        symlink(readlink($source), $destination);
+
+        return;
+    }
+
+    if (is_file($source)) {
+        copy($source, $destination);
+
+        return;
+    }
+
+    if (!is_dir($destination)) {
+        mkdir($destination, 0777, true);
+    }
+
+    foreach (scandir($source) as $entry) {
+        if ($entry === '.' || $entry === '..' || $entry === '.git' || $entry === 'vendor') {
+            continue;
+        }
+
+        copyTree($source . '/' . $entry, $destination . '/' . $entry);
+    }
+}
+
+copyTree($root, $isolatedRoot);
+$root = $isolatedRoot;
+
 // Step 1: Remove lock and vendor
 if (file_exists($root . '/composer.lock')) {
     unlink($root . '/composer.lock');
@@ -74,7 +105,6 @@ function () use ($root): void {
 $results['composer_update_output'] = implode("\n", array_slice($updateOutput, -5));
 
 // Step 3: Run test suite (exclude destructive group to avoid recursion)
-$php = '/opt/homebrew/Cellar/php/8.5.1_2/bin/php';
 exec(
     'cd ' . escapeshellarg($root) . ' && ' . $php . ' vendor/bin/pest --parallel --exclude-group=integration-destructive 2>&1',
     $testOutput,
@@ -96,6 +126,8 @@ function () use ($root): void {
             $php . ' ' . escapeshellarg($scriptFile)
             . ' ' . escapeshellarg($root)
             . ' ' . escapeshellarg($resultFile)
+            . ' ' . escapeshellarg($php)
+            . ' ' . escapeshellarg($isolatedRoot)
             . ' 2>/dev/null',
         );
     
@@ -121,7 +153,7 @@ function () use ($root): void {
 })->group('integration-destructive');
 
 it('runs the full test suite and all tests pass', function () use ($root): void {
-    $php = '/opt/homebrew/Cellar/php/8.5.1_2/bin/php';
+    $php = PHP_BINARY;
     $output = [];
     $exitCode = 0;
     exec(
diff --git a/tests/ReleaseScriptTest.php b/tests/ReleaseScriptTest.php
index 7499ffe0..f8eef484 100644
--- a/tests/ReleaseScriptTest.php
+++ b/tests/ReleaseScriptTest.php
@@ -67,12 +67,10 @@
         ->and($contents)->toContain('Expected X.Y.Z');
 });
 
-it('validates PHP version is 8.5+ (checks /opt/homebrew/Cellar/php/8.5.1_2/bin/php or system php)', function () use ($script): void {
-    // Script should check the Homebrew PHP path first, then fall back to system php
+it('validates PHP version is 8.5+ (uses PHP_BIN env var or defaults to system php)', function () use ($script): void {
     $contents = file_get_contents($script);
 
-    expect($contents)->toContain('/opt/homebrew/Cellar/php/8.5.1_2/bin/php')
-        ->and($contents)->toContain('PHP_BIN="php"')
+    expect($contents)->toContain('PHP_BIN="${PHP_BIN:-php}"')
         ->and($contents)->toContain('8.5');
 });