refactor(vite-config): drop the inert duplicate-vite Plugin cast

apps/api/ui/vite.config.ts

@@ -1,18 +1,15 @@
 import { APPS } from '@epicenter/constants/apps';
 import { sveltekit } from '@sveltejs/kit/vite';
 import tailwindcss from '@tailwindcss/vite';
-import { defineConfig, type PluginOption } from 'vite';
+import { defineConfig } from 'vite';
 
 // Dashboard is same-origin with API: in prod, served as static assets from
 // `api.epicenter.so/dashboard`; in dev, the proxy below routes /api and /auth
 // to the local Worker so the browser only sees same-origin requests.
 const DASHBOARD_DEV_PORT = 5178;
 
 export default defineConfig({
-	// Each workspace has its own physical vite install (same version), so the
-	// plugins' `Plugin` type is nominally distinct from this config's
-	// `PluginOption`. Cast until the installs dedupe to one vite.
-	plugins: [sveltekit(), tailwindcss()] as PluginOption[],
+	plugins: [sveltekit(), tailwindcss()],
 	server: {
 		port: DASHBOARD_DEV_PORT,
 		strictPort: true,

apps/matter/vite.config.ts

@@ -1,14 +1,11 @@
 import { sveltekit } from '@sveltejs/kit/vite';
 import tailwindcss from '@tailwindcss/vite';
-import { defineConfig, type PluginOption } from 'vite';
+import { defineConfig } from 'vite';
 
 // Matter is desktop-only (Tauri). There is no browser build to branch on, so the
 // app imports `@tauri-apps/*` directly; develop with `bun run tauri dev`.
 export default defineConfig({
-	// Each workspace has its own physical vite install (same version), so the
-	// plugins' `Plugin` type is nominally distinct from this config's
-	// `PluginOption`. Cast until the installs dedupe to one vite.
-	plugins: [sveltekit(), tailwindcss()] as PluginOption[],
+	plugins: [sveltekit(), tailwindcss()],
 	clearScreen: false,
 	server: {
 		// Tauri's devUrl points here; the port must be fixed.

apps/skills/vite.config.ts

@@ -1,12 +1,9 @@
 import { sveltekit } from '@sveltejs/kit/vite';
 import tailwindcss from '@tailwindcss/vite';
-import { defineConfig, type PluginOption } from 'vite';
+import { defineConfig } from 'vite';
 
 export default defineConfig({
-	// Each workspace has its own physical vite install (same version), so the
-	// plugins' `Plugin` type is nominally distinct from this config's
-	// `PluginOption`. Cast until the installs dedupe to one vite.
-	plugins: [sveltekit(), tailwindcss()] as PluginOption[],
+	plugins: [sveltekit(), tailwindcss()],
 	resolve: {
 		dedupe: ['yjs'],
 	},

packages/vite-config/src/index.ts

@@ -18,12 +18,14 @@ import { searchForWorkspaceRoot, type UserConfig } from 'vite';
  */
 export function workspaceAppViteConfig(app: { port: number }): UserConfig {
 	return {
-		// A consuming app's `@sveltejs/kit` and this package can resolve different
-		// bun peer-variant copies of the same `vite` version (`vite@7.3.5` vs
-		// `vite@7.3.5+<hash>`), whose `Plugin` types are then nominally unrelated,
-		// so `svelte-check` rejects the array against this package's `UserConfig`.
-		// One vite runs at runtime; bridge the array to this package's plugin type.
-		plugins: [sveltekit(), tailwindcss()] as UserConfig['plugins'],
+		// No cast: the isolated install resolves a single `vite` peer-variant that
+		// every package (this one, the app, @sveltejs/kit, @tailwindcss/vite)
+		// symlinks to, so the plugins' `Plugin` type matches this `UserConfig`. If
+		// CI ever reports `Two different types with this name exist, but they are
+		// unrelated` on this line again, bun re-split `vite` into peer-variants
+		// (`vite@7.3.5+<hashA>` vs `+<hashB>`); restore `as UserConfig['plugins']`
+		// here, the one place every workspace app's plugins come from.
+		plugins: [sveltekit(), tailwindcss()],
 		resolve: {
 			dedupe: ['yjs'],
 		},