chore: register mcp-client e2e entries in knip config

Add the mcp-client workspace override so knip recognises the e2e test
file, fixture-server entry, and the bin-only devDeps (server-everything,
server-filesystem) that are invoked at runtime rather than imported.

knip.json

@@ -69,6 +69,11 @@
     "packages/fs/tool-fs": {
       "entry": ["tests/**/*.spec.ts", "tests/**/*.e2e.ts"],
       "project": ["src/**/*.ts", "tests/**/*.ts"]
+    },
+    "packages/mcp/mcp-client": {
+      "entry": ["tests/**/*.spec.ts", "tests/**/*.e2e.ts", "tests/fixture-server.ts"],
+      "project": ["src/**/*.ts", "tests/**/*.ts"],
+      "ignoreDependencies": ["@modelcontextprotocol/server-everything", "@modelcontextprotocol/server-filesystem"]
     }
   }
 }