## Why
Executor-owned MCP configuration can include required servers that are unavailable. Guardian review sessions should not attempt to discover those servers or let them block an approval review.
## What changed
- Skip projecting MCP servers from selected executors when the session source is a Guardian reviewer.
- Preserve executor MCP discovery for regular thread sessions.
## Testing
Added an app-server integration test that configures an unreachable required executor MCP server and verifies that Guardian can still review an escalated command and return its decision.
GitOrigin-RevId: 5b712a3ee04e6896d5ca0cff39a32dd8e0fe0132