Refactor cards into modular per-file definitions

Split the monolithic CARD_LIBRARY into one file per card under
cards/definitions/, aggregated by a barrel (definitions/index.ts).
card-library.ts now indexes ALL_CARDS by id with a duplicate-id guard.
Public API (CARD_LIBRARY, getCard, STARTER_DECK) and all card ids are
unchanged, so consumers and save data are unaffected.

Also ignore the .vite build cache.

.gitignore

@@ -10,6 +10,7 @@ lerna-debug.log*
 node_modules
 dist
 dist-ssr
+.vite
 *.local
 
 # Editor directories and files