feat: add php rule pack

rules/php/security.md

@@ -0,0 +1,33 @@
+---
+paths:
+  - "**/*.php"
+  - "**/composer.lock"
+  - "**/composer.json"
+---
+# PHP Security
+
+> This file extends [common/security.md](../common/security.md) with PHP specific content.
+
+## Input and Output
+
+- Validate request input at the framework boundary (`FormRequest`, Symfony Validator, or explicit DTO validation).
+- Escape output in templates by default; treat raw HTML rendering as an exception that must be justified.
+- Never trust query params, cookies, headers, or uploaded file metadata without validation.
+
+## Database Safety
+
+- Use prepared statements (`PDO`, Doctrine, Eloquent query builder) for all dynamic queries.
+- Avoid string-building SQL in controllers/views.
+- Scope ORM mass-assignment carefully and whitelist writable fields.
+
+## Secrets and Dependencies
+
+- Load secrets from environment variables or a secret manager, never from committed config files.
+- Run `composer audit` in CI and review new package maintainer trust before adding dependencies.
+- Pin major versions deliberately and remove abandoned packages quickly.
+
+## Auth and Session Safety
+
+- Use `password_hash()` / `password_verify()` for password storage.
+- Regenerate session identifiers after authentication and privilege changes.
+- Enforce CSRF protection on state-changing web requests.