fix(visual-parity): exclude transitive deps from Vite optimizeDeps in both renderers

Exclude markdown-it, clsx, and signal-utils/* from pre-bundling in both
the React and Lit dev servers to avoid stale cache / duplicate module
instances. Also update cache-clearing instructions in PARITY.md.

Author: lukasmoschitz

renderers/react/visual-parity/PARITY.md

@@ -165,7 +165,7 @@ This happens when Vite's dependency optimization cache becomes stale, typically
 **Fix:** Clear the Vite cache and restart:
 ```bash
 # From renderers/react/visual-parity/
-rm -rf node_modules/.vite react/node_modules/.vite lit/node_modules/.vite
+rm -rf node_modules/.vite react/node_modules/.vite lit/node_modules/.vite ../node_modules/.vite
 npm run dev:react  # or dev:lit
 ```
 

renderers/react/visual-parity/lit/vite.config.ts

@@ -7,8 +7,16 @@ export default defineConfig({
     strictPort: true,
   },
   optimizeDeps: {
-    // Don't pre-bundle @a2ui/lit to avoid duplicate module instances
-    exclude: ['@a2ui/lit'],
+    // Don't pre-bundle @a2ui/lit or its deps to avoid duplicate module instances
+    exclude: [
+      '@a2ui/lit',
+      'markdown-it',
+      'clsx',
+      'signal-utils/array',
+      'signal-utils/map',
+      'signal-utils/object',
+      'signal-utils/set',
+    ],
   },
   esbuild: {
     // Enable decorator support

renderers/react/visual-parity/react/vite.config.ts

@@ -10,7 +10,16 @@ export default defineConfig({
     strictPort: true,
   },
   optimizeDeps: {
-    exclude: ['@a2ui/react', '@a2ui/lit', 'markdown-it'],
+    exclude: [
+      '@a2ui/react',
+      '@a2ui/lit',
+      'markdown-it',
+      'clsx',
+      'signal-utils/array',
+      'signal-utils/map',
+      'signal-utils/object',
+      'signal-utils/set',
+    ],
   },
   resolve: {
     alias: {