pull_request_template.md

What changed

Why

Checklist

• bash tests/run.sh passes locally with vendor/ installed (the round-trip and PHAR checks skip themselves without it).
• .php files were edited through bin/php-ast-edit, not sed, regex, or raw string replacement.
• Version changes went into the root plugin.json and .claude-plugin/plugin.json was regenerated, not hand-edited.
• New or changed operations are documented in skills/php-structured-edit/references/operations.md.
• SKILL.md stays under 500 words and every references/*.md remains reachable from it.
• Commits follow Conventional Commits and are signed.