[bug] Potential resource leak due to unclosed listener in mcp.go

[docker-agent]

🟠 high - bug

File: cmd/root/mcp.go (line 48)

Code

ln, err := listenAndCloseOnCancel(ctx, f.listenAddr)
if err != nil {
	return err
}

return mcp.StartHTTPServer(ctx, agentFilename, f.agentName, &f.runConfig, ln)

Problem

The ln listener is created by listenAndCloseOnCancel and passed to mcp.StartHTTPServer. While listenAndCloseOnCancel spawns a goroutine to close the listener when the context is cancelled, if mcp.StartHTTPServer returns an error before the context is cancelled, or if it doesn't explicitly close the listener, the listener may remain open, causing a resource leak.

Suggested Fix

Add a defer ln.Close() right after the listener is successfully created to ensure it's always closed when the function exits, regardless of how mcp.StartHTTPServer exits.

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Found by nightly codebase scan