feat(agents): Add data-migration-expert and deployment-verification-agent

New review agents for validating database migrations and risky data deployments:

- data-migration-expert: Validates ID mappings match production reality, checks
  for swapped values, verifies rollback safety, provides SQL verification snippets

- deployment-verification-agent: Produces Go/No-Go deployment checklists with
  pre/post-deploy SQL queries, data invariants, rollback procedures, monitoring

Updated /workflows:review to conditionally run these agents when PRs contain
database migrations (db/migrate/*.rb), data backfills, or ID/enum mappings.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

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

@@ -1,7 +1,7 @@
 {
   "name": "compound-engineering",
-  "version": "2.11.0",
-  "description": "AI-powered development tools. 25 agents, 17 commands, 12 skills, 2 MCP servers for code review, research, design, and workflow automation.",
+  "version": "2.12.0",
+  "description": "AI-powered development tools. 27 agents, 17 commands, 12 skills, 2 MCP servers for code review, research, design, and workflow automation.",
   "author": {
     "name": "Kieran Klaassen",
     "email": "kieran@every.to",