Release v1.2.0

Changed

• Debug mode now rethrows view-renderer errors instead of swallowing them.
• Plain-text fallback no longer exposes exception details.
• HTTP status codes are normalized to the 100-599 range.
• View renderer callables are normalized to closures.
• Template base path is configurable via constructor.
• Status template file tests now use a temp directory.
• README updated with behavior notes and template path example.
• PHPUnit configuration migrated; .phpunit.cache ignored.
• Updated dependency codemonster-ru/http to ^2.0.