Enforce stricter PR title checking

Editor assessment

Competent and appropriately scoped. `ci` fits a change to PR title linting perfectly, and 'enforce stricter PR title checking' is imperative, lowercase, and clear about both the action (enforce) and direction (stricter) - future contributors hitting the new rule will find the commit that introduced it easily. The body's gitmoji entries (:zap: 'Enforce stricter PR title checking', :fire: 'Remove code fence') restate the header in emoji shorthand and note a small cleanup; the emoji style is a house convention outside the spec's vocabulary but harmless. Missing detail: what does 'stricter' mean concretely - a new type enumeration? length limits? scope requirements? One body line enumerating the added rules would save every future violator a diff read. Structure is sound throughout, with valid token usage and separation.