fix(settings): name descending size sort explicitly

The library sort setting used `size` for largest-first sorting while the
ascending option used `sizeAsc`. That made the pair asymmetric and left the
current settings model carrying a legacy-looking key.

Rename the current descending key to `sizeDesc` in the type, menu, and sort
logic. Stored `size` values are normalized to `sizeDesc` on read, so existing
users keep the same largest-first behavior while new writes use the explicit
key.

Test Plan:
- deno task build
- RUSTC_WRAPPER= CARGO_BUILD_RUSTC_WRAPPER= just build
- git diff --check

Refs: local review feedback

crates/lanspread-tauri-deno-ts/src/lib/gameState.ts

@@ -213,7 +213,7 @@ export const applyFilterAndSort = (
     switch (sort) {
         case 'az':
             return [...list].sort((a, b) => a.name.localeCompare(b.name));
-        case 'size':
+        case 'sizeDesc':
             return [...list].sort((a, b) => b.size - a.size);
         case 'sizeAsc':
             return [...list].sort((a, b) => a.size - b.size);

crates/lanspread-tauri-deno-ts/src/lib/types.ts

@@ -62,7 +62,7 @@ export interface GamesListPayload {
 export type GameFilter = 'all' | 'local' | 'installed';
 
 /** Library sort order. */
-export type GameSort = 'az' | 'size' | 'sizeAsc' | 'status';
+export type GameSort = 'az' | 'sizeDesc' | 'sizeAsc' | 'status';
 
 /** Visual state of a card. Derived from install/download flags. */
 export type DerivedState = 'installed' | 'local' | 'none' | 'busy';