feat: add ssh-connection-string option for container SSH access

Add internal -ssh-connection-string flag to pass SSH hostname from dockerimg
to sketch container, allowing the UI to display the correct SSH connection
string based on SSH Theater configuration rather than generating it locally.

Co-Authored-By: sketch <hello@sketch.dev>
Change-ID: s1872f10f74da5f9bk
diff --git a/dockerimg/dockerimg.go b/dockerimg/dockerimg.go
index 12c65f3..ac07fa8 100644
--- a/dockerimg/dockerimg.go
+++ b/dockerimg/dockerimg.go
@@ -561,6 +561,8 @@
 		"-branch-prefix="+config.BranchPrefix,
 		"-link-to-github="+fmt.Sprintf("%t", config.LinkToGitHub),
 	)
+	// Set SSH connection string based on session ID for SSH Theater
+	cmdArgs = append(cmdArgs, "-ssh-connection-string=sketch-"+config.SessionID)
 	if config.Model != "" {
 		cmdArgs = append(cmdArgs, "-model="+config.Model)
 	}