docs: add comprehensive pnpm + release-it migration plan

- Document current state analysis and pain points
- Phase 1: pnpm + workspace protocol migration steps
- Phase 2: release-it integration for automated releases
- Include testing strategy, rollback plans, and FAQ
- Timeline estimates and comparison tables
- Detailed step-by-step instructions with code examples

This plan addresses manual version syncing across 102 packages
and replaces Lerna with modern, actively-maintained tooling.

Author: balzss

.gitignore

@@ -17,3 +17,6 @@ __build__
 tsconfig.build.tsbuildinfo
 
 .pnp.*
+
+.claude/settings.local.json
+.playwright-mcp