## Why
Orchestrator skill caches were tied to the entire MCP connection set, so runtime updates could discard cached catalogs and contents even when the Apps connection was reused. Plugin changes still need to refresh those resources without requiring a reconnect.
## What changed
Key orchestrator skill caches by the Apps server connection and an explicit invalidation generation. Preserve cached resources while that identity stays unchanged, and invalidate them on MCP runtime refresh requests or configuration refreshes. Replacing the connection also changes the cache identity.
## Testing
Extend the production-turn integration test to verify cache reuse across ordinary turns and approval-policy changes, refreshed skill contents after plugin invalidation without reconnecting, and fresh resource requests after a forced reconnect.
GitOrigin-RevId: 43ce059972369c4c735742e8224b60a692244b02
29e6bc814e