feat(mcp-server): scaffold @bytelyst/mcp-server on port 4006 with 10 tools across 4 namespaces
- platform.telemetry.{query,clusters,metrics}
- platform.diagnostics.sessions.{list,create,get,update,getLogs,getTraces}
- extraction.{run,models,cacheStats}
- support.createDebugPack (compound: clusters + optional diag session + markdown summary)
- Role-gated (viewer/admin/super_admin), JWT auth via platform-service secret
- Proxies to platform-service:4003 and extraction-service:4005
- 4 Vitest tests passing, tsc --noEmit clean