Add prototypes folder to test new functionality in (#6081)

# Description of Changes
Add prototypes folder to test new functionality in. This build of the
app is spawnable with `npm run dev:prototypes`.

Currently just contains a very developer-y chat interface to help us
develop & explore the AI backend before we make the frontend for it for
real.

frontend/tsconfig.prototypes.vite.json

@@ -0,0 +1,23 @@
+{
+  "extends": "./tsconfig.proprietary.vite.json",
+  "compilerOptions": {
+    "paths": {
+      "@app/*": [
+        "src/prototypes/*",
+        "src/proprietary/*",
+        "src/core/*"
+      ],
+      "@proprietary/*": ["src/proprietary/*"],
+      "@core/*": ["src/core/*"]
+    }
+  },
+  "exclude": [
+    "src/core/**/*.test.ts*",
+    "src/core/**/*.spec.ts*",
+    "src/proprietary/**/*.test.ts*",
+    "src/proprietary/**/*.spec.ts*",
+    "src/desktop",
+    "src/saas",
+    "node_modules"
+  ]
+}