everything-server: identify with an explicit version

Unversioned servers now report an empty version string, and the
conformance referee's identity check (sep-2575-server-identifies-in-
result-meta) treats an empty version as an unidentified server. A
conformance fixture should fully identify itself; use the example
package's own version.

No-Verification-Needed: one-line example fixture config; conformance CI is the verification

Author: maxisbey

examples/servers/everything-server/mcp_everything_server/server.py

@@ -102,6 +102,7 @@ async def replay_events_after(self, last_event_id: EventId, send_callback: Event
 
 mcp = MCPServer(
     name="mcp-conformance-test-server",
+    version="0.1.0",
     request_state_security=RequestStateSecurity(keys=[_REQUEST_STATE_KEY]),
 )