## Why
Dormant MCP servers with usable cached tool catalogs prevented binding reuse, causing each model step to capture a new binding even when the catalog was unchanged.
## What changed
Track dormant catalog revisions alongside ready client revisions so bindings can be reused until the catalog changes or the server starts. Explicit server and plugin requirements still trigger binding capture and startup. Check cached catalog availability without cloning tool definitions.
## Testing
Extend the lazy-startup integration test to verify that two model steps share one binding while the server stays dormant, and that starting the server invalidates that binding.
GitOrigin-RevId: ef0469a85000f84a928946c24350e3bda1522fb5
jif
20f109eadb