add: absorb uno-online as regular subdirectory

UNO card game web app (Node.js/React) with Miku bot integration.
Previously an independent git repo (fork of mizanxali/uno-online).
Removed .git/ and absorbed into main repo for unified tracking.

Includes bot integration code: botActionExecutor, cardParser,
gameStateBuilder, and server-side bot action support.
37 files, node_modules excluded via local .gitignore.

uno-online/.gitignore

@@ -0,0 +1,4 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+node_modules/