Exclude AppleDouble companions from test discovery (#11)

tsconfig.app.json

@@ -29,5 +29,12 @@
     "jsx": "react-jsx",
     "types": ["vite/client", "vitest/globals"]
   },
-  "include": ["src"]
+  "include": ["src"],
+  "exclude": [
+    "node_modules",
+    "bower_components",
+    "jspm_packages",
+    "**/._*",
+    "**/._*/**"
+  ]
 }