feat: Add proof skill and optional Proof sharing in plan/brainstorm workflows (v2.37.0)

Merges feat/proof-integration with conflict resolution:
- proof skill for creating/editing/sharing markdown docs via Proof API
- "Share to Proof" added as opt-in menu option in /workflows:brainstorm Phase 4
- "Share to Proof" added as opt-in menu option in /workflows:plan Post-Generation Options
- Bumped version 2.36.0 → 2.37.0 to avoid conflict with OpenClaw/Qwen/Windsurf release

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

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

.claude-plugin/marketplace.json

@@ -11,8 +11,8 @@
   "plugins": [
     {
       "name": "compound-engineering",
-      "description": "AI-powered development tools that get smarter with every use. Make each unit of engineering work easier than the last. Includes 29 specialized agents, 22 commands, and 19 skills.",
-      "version": "2.35.2",
+      "description": "AI-powered development tools that get smarter with every use. Make each unit of engineering work easier than the last. Includes 29 specialized agents, 22 commands, and 20 skills.",
+      "version": "2.37.0",
       "author": {
         "name": "Kieran Klaassen",
         "url": "https://github.com/kieranklaassen",