Wire useTranslation('ui') into all three Z2 pages:
- GameBoard: loading, reconnecting, stats drawer, Winding Dark warning
- Guild: full coverage — create modal, withdraw modal, directory,
  member rows, leader controls, applications, all buttons/labels
- Leaderboard: tabs, filters, sort headers, Race to Max, PvP rankings,
  empty states, column headers

All 4 locales updated (EN/KO/JA/ZH) with ~80 new keys each.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

"Tile Details", "You have not yet spawned", "An error occurred",
and "In order to begin battling, you must spawn" were hardcoded
despite the components having useTranslation hooks. Added keys
to gameBoard namespace in all 4 locales (EN/KO/JA/ZH).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add overflow: hidden to header Grid. CJK nav text widths caused
the logo to bleed into the map panel below via negative margins.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

21 combat.* keys, 4 tile.* keys, 5 zone.* keys were used in t()
calls but missing from all locale JSON files — causing raw keys
like "combat.moveToFind" and "tile.players" to render in the UI.

Also translate zone names ("Dark Cave" / "Windy Peaks") via i18n
in MapContext instead of hardcoded English.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>