[2.9.4] Improve /work command screenshot documentation

- Made capturing screenshots REQUIRED for any UI changes
- Updated to use imgup skill with pixhost as default host
- Clarified what to capture: new screens, before/after, Figma matches
- Removed outdated curl/0x0.st reference

🤖 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": "2.9.3",
+  "version": "2.9.4",
   "description": "AI-powered development tools. 24 agents, 19 commands, 11 skills, 2 MCP servers for code review, research, design, and workflow automation.",
   "author": {
     "name": "Kieran Klaassen",