Clean up code. Reorganize files. Port stuff from other branches. + more

This turns the project into a monorepo using pnpm workspaces,
dramatically simplifying the build process. It also fixes a lot of bugs
and just generally makes the codebase a lot cleaner.

example-app/nuxt.config.ts

@@ -19,7 +19,7 @@ export default defineNuxtConfig({
             }
         },
     },
-    modules: ['@unocss/nuxt', ['nuxt-ssr-lit', { litElementPrefix: 'pow-' }]],
+    modules: ['@unocss/nuxt', ['nuxt-ssr-lit', { litElementPrefix: 'impost-' }]],
 
     nitro: {
         moduleSideEffects: ["@impost/widget"],
@@ -28,17 +28,9 @@ export default defineNuxtConfig({
         },
     },
 
-    imports: {
-        transform: {
-            // only necessary in the monorepo since vite is going out to the
-            // source of the widget and transforming it and clobbering it.
-            exclude: [/impost/],
-        }
-    },
-
     vue: {
         compilerOptions: {
-            isCustomElement: (tag) => tag.includes('pow-'),
+            isCustomElement: (tag) => tag.startsWith('impost-'),
         },
     },