diff --git a/frontend/vite.config.ts b/frontend/vite.config.ts
index a0d1e977..18240c74 100644
--- a/frontend/vite.config.ts
+++ b/frontend/vite.config.ts
@@ -6,8 +6,15 @@ import { defineConfig } from 'vitest/config';
 import { playwright } from '@vitest/browser-playwright';
 import { sveltekit } from '@sveltejs/kit/vite';
 import { viteStaticCopy } from 'vite-plugin-static-copy';
+import { fileURLToPath } from 'node:url';
 
 export default defineConfig({
+	resolve: {
+		alias: {
+			// Shared browser-test mock bodies, imported into sync vi.mock factories. See ADR-012.
+			$mocks: fileURLToPath(new URL('./src/__mocks__', import.meta.url))
+		}
+	},
 	optimizeDeps: {
 		include: ['pdfjs-dist', '@tiptap/core', '@tiptap/starter-kit', '@tiptap/extension-mention']
 	},
diff --git a/frontend/vitest.client-coverage.config.ts b/frontend/vitest.client-coverage.config.ts
index dc822281..b7b1ad57 100644
--- a/frontend/vitest.client-coverage.config.ts
+++ b/frontend/vitest.client-coverage.config.ts
@@ -4,6 +4,7 @@ import tailwindcss from '@tailwindcss/vite';
 import { defineConfig } from 'vitest/config';
 import { playwright } from '@vitest/browser-playwright';
 import { sveltekit } from '@sveltejs/kit/vite';
+import { fileURLToPath } from 'node:url';
 
 // Standalone config for browser-project Istanbul coverage.
 // Uses a dedicated root-level coverage block because Vitest 4 ignores
@@ -11,6 +12,12 @@ import { sveltekit } from '@sveltejs/kit/vite';
 // Plugins mirrored from vite.config.ts: tailwindcss, sveltekit, devtoolsJson, paraglideVitePlugin
 // Update here whenever vite.config.ts plugins change.
 export default defineConfig({
+	resolve: {
+		alias: {
+			// Shared browser-test mock bodies, imported into sync vi.mock factories. See ADR-012.
+			$mocks: fileURLToPath(new URL('./src/__mocks__', import.meta.url))
+		}
+	},
 	optimizeDeps: {
 		include: ['pdfjs-dist', '@tiptap/core', '@tiptap/starter-kit', '@tiptap/extension-mention']
 	},