fix asset paths for subdirectory hosting, bump to 0.1.1

The deployed build is served from /file/<name>-<version>/, but Vite
emitted absolute /assets/ URLs and BootScene loaded sprites from
/sprites/. Set base: "./" in vite.config.ts and make the sprite
paths relative so everything resolves next to index.html.

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "trickster-tiles",
   "private": true,
-  "version": "0.1.0",
+  "version": "0.1.1",
   "type": "module",
   "scripts": {
     "dev": "vite",