Merge skin/effects pickers into one lobby Cosmetics modal (#4617)

## What

Replaces the three lobby cosmetic buttons (skin, flag, effects) with
two: **Flag** and **Cosmetics**. The new Cosmetics button opens a single
tabbed modal (`#modal=cosmetics`) with:

- **Skins** — the combined patterns + image-skins grid (from
TerritoryPatternsModal)
- **Effects** — all effect types via the tabbed effects-grid, same
layout as the Store

## Changes

- New `CosmeticsModal` and `CosmeticsInput` (lobby button previews the
selected skin/pattern, shows a "Cosmetics" label on defaults, hidden on
CrazyGames via `no-crazygames`)
- Removed `TerritoryPatternsModal`, `EffectsModal`, `PatternInput`,
`EffectsInput` and their wiring in Main.ts / index.html / LangSelector
- Selecting a skin or pattern no longer closes the modal — the tile
highlight moves to the new selection (matches the Effects tab behavior)
- i18n: added `cosmetics.title/button_title/search`; removed the keys
orphaned by the deleted components

## Notes

- Deep links to the old `#modal=territory-patterns` and `#modal=effects`
no longer resolve
- A follow-up PR (crowns cosmetic) stacks on this branch

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

index.html

@@ -282,16 +282,11 @@
           inline
           class="hidden w-full h-full page-content relative z-50"
         ></flag-input-modal>
-        <territory-patterns-modal
-          id="territory-patterns-modal"
+        <cosmetics-modal
+          id="cosmetics-modal"
           inline
           class="hidden w-full h-full page-content relative z-50"
-        ></territory-patterns-modal>
-        <effects-modal
-          id="effects-modal"
-          inline
-          class="hidden w-full h-full page-content relative z-50"
-        ></effects-modal>
+        ></cosmetics-modal>
         <ranked-modal
           id="page-ranked"
           inline