refactor(lint): rewrite structural linters from Ruby to PHP

Fold scripts/lint and scripts/linters/*.rb into a standalone Composer
project under scripts/linters/, matching the scripts/plugin-class-classifier/
convention. Uses no external packages, only PHP + Composer autoloading.

Verified byte-for-byte identical output against the original Ruby
implementation, both on the current repo (all linters pass) and on a
synthetic fixture exercising every violation type.

Entry point moves from `scripts/lint` to `scripts/linters/lint`.

1 files changed, 39 insertions, 0 deletions

diff --git a/scripts/linters/src/Runner.php b/scripts/linters/src/Runner.php
new file mode 100644
index 00000000..ae2d84ed
--- /dev/null
+++ b/scripts/linters/src/Runner.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shirabe\Lint;
+
+final class Runner
+{
+    /** @param list<array{0: Linter, 1: list<string>}> $linters */
+    public function __construct(
+        private readonly string $rootDir,
+        private readonly array $linters,
+    ) {
+    }
+
+    public function run(): bool
+    {
+        $allPassed = true;
+
+        foreach ($this->linters as [$linter, $excludes]) {
+            echo "===== {$linter->name()} =====\n";
+
+            $errors = $linter->check($this->rootDir, $excludes);
+            if ($errors === []) {
+                echo "Passed.\n";
+            } else {
+                echo $linter->failureIntro(), "\n";
+                foreach ($errors as $error) {
+                    echo "  {$error}\n";
+                }
+                $allPassed = false;
+            }
+
+            echo "\n";
+        }
+
+        return $allPassed;
+    }
+}