Type cleanup and LanguageContext introduction

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Overview

Consolidate duplicate type definitions across hooks and replace
prop drilling for language switching with useContext.

Background

• Pagination type is duplicated between useTopPage and domain/types.ts
• Language (ja/en) toggling is passed down via prop drilling

Child Issues

• Refactor: Remove duplicate types definition #297
• Refactor: Introduce LanguageContext to eliminate prop drilling #298