feat: add headed/headless mode option to test-browser

- Add Step 0 asking user if they want to watch browser tests
- Headed mode opens visible browser window
- Headless mode runs faster in background
- Bump version to 2.25.0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

plugins/compound-engineering/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "compound-engineering",
-  "version": "2.24.0",
+  "version": "2.25.0",
   "description": "AI-powered development tools. 27 agents, 20 commands, 14 skills, 1 MCP server for code review, research, design, and workflow automation.",
   "author": {
     "name": "Kieran Klaassen",