Fix: Move CSS to root styles/ folder for FoundryVTT compatibility

The issue: CSS was in dist/styles/ but FoundryVTT expects module CSS
at the root level or in a standard location.

Changes:
- Build CSS to styles/scrying-pool.css (root level) instead of dist/styles/
- Update module.json to reference styles/scrying-pool.css
- Update .gitignore to track styles/scrying-pool.css
- Update build script in package.json

This ensures FoundryVTT can find and load the CSS file properly in live sessions.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

module.json

@@ -17,7 +17,7 @@
     "module.js"
   ],
   "styles": [
-    "dist/styles/scrying-pool.css"
+    "styles/scrying-pool.css"
   ],
   "languages": [
     {