Ignore local Windows client/data assets and .claude config

Client/, 3Ddata*, KTRose_pre-evo.zip are large local-only assets used
for end-to-end login/game testing, not part of the server source tree.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -1,3 +1,13 @@
 build/
 build-*/
 .env
+
+# Windows game client + data assets, kept locally for end-to-end login/game
+# testing but not part of the server source tree.
+/Client/
+/3Ddata/
+/3Ddata.zip
+/KTRose_pre-evo.zip
+
+# Claude Code project-local config
+/.claude/