feat(dex): add search, sorting, and filters to Pokédex and Catch Log

[KillianHzr]

Summary

This PR introduces comprehensive search, sorting, and filtering capabilities to both the Pokédex grid and the Catch Log (Journal de captures) in the Collection tab:

• Search Bar: Live search by Pokémon name (case- and diacritic-insensitive), Pokédex number (e.g. 25 or #25), and multilingual translations stored in saves. Includes a clear button (xmark.circle.fill).
• Shiny Filter: Quick toggle button to filter species captured as shiny (in Pokédex) or individual shiny catches (in Catch Log), with clear visual highlight when active.
• Sorting Options:
  • Pokédex: Number (Low to High - default), Number (High to Low), Name (A–Z), Name (Z–A), and Rarity (High to Low).
  • Catch Log: Most Recent (default, active companion pinned first), Oldest First, Number (Low to High), Number (High to Low), Name (A–Z), Name (Z–A), and Rarity (High to Low).
• Empty State: Displays a friendly empty search result state with an icon, message, and a "Reset filters" button to quickly restore the full collection.
• Localization: All UI copy and sort option labels are localized across all 7 supported languages (ko, en, ja, es, fr, pt, de).
• Tests: Comprehensive unit tests covering search matching, sort orders, and filter combinations in DexSearchAndFilterTests.swift.

Type of change

• Bug fix
• New feature
• Refactor / cleanup
• Documentation
• Other:

UI changes

Before	After
The Pokédex grid only displayed species in fixed ascending numerical order without search, custom sorting, or shiny filtering. The Catch Log only displayed entries in chronological order.	A compact toolbar sits below the Collection subtab picker with a search field, a shiny filter toggle, and a sort menu. When no matches are found, a clear empty state with a "Reset filters" button is shown. Cell sizes remain balanced within the 520pt fixed popover height.

Checklist

• swift build and swift test pass locally
• PR title and description are written in English
• UI changes are described above (before/after — images optional)
• No copyrighted assets, secrets, or private tooling references are committed (see CONTRIBUTING)
• Tests were added or updated for this change