feat: v1.4.0 — review code, web search grounding, responsive preview

New features:
- Review Code button sends generated code back to AI for review
- Web search grounding via SearXNG (toggle in toolbar, enriches prompts)
- Responsive preview with device size selector (Full/Desktop/Tablet/Mobile)
- /api/search proxy route

Fixes:
- Model selector text color now white on dark theme
- Post-coding button text overflow (shorter labels + min-w-0)
- Duplicate activateArtifact button suppressed when action row shows

package.json

@@ -1,6 +1,6 @@
 {
   "name": "promptarch",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "description": "Transform vague ideas into production-ready prompts and PRDs",
   "scripts": {
     "dev": "next dev",