[BUG] strata auth succeeds silently when server isn't connected

[deepak0x]

1. Describe the bug

Running strata auth <server> exits 0 with no output when the server exists in config but hasn't actually connected. The user thinks auth worked. It didn't — nothing happened.

authenticate_server() in mcp_client_manager.py:73 checks if server_name in self.active_clients but there's no else branch. If the condition is false, the function just returns None. The CLI at cli.py:168 treats that as success.

2. To reproduce

1. strata add --type sse my-server http://localhost:9999/sse
2. Don't start the server (so it never connects to strata)
3. strata auth my-server
4. Command exits 0, prints nothing. No error, no success message.

3. Expected behavior

Non-zero exit code and an error message like "Server 'my-server' is not connected".

4. Environment

• Affected MCP Server Name: open-strata (core)
• MCP Server Version/Commit: main HEAD
• Klavis Service:
  • Self-hosted