fix: check only final responses in AllSucceeded to determine deployment success

The CLI was incorrectly reporting "some deployments failed" even when
deployments succeeded. This was because AllSucceeded() checked if every
response had StatusCompleted, but the Responses slice contains all
messages including intermediate ones like "started". Since started !=
completed, it returned false.

Now AllSucceeded() only examines final responses (using IsFinal()) and
checks that each host's final status is completed.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/cli/deploy_test.go

@@ -49,6 +49,40 @@ func TestDeployResult_AllSucceeded(t *testing.T) {
 			errors: []error{nil}, // placeholder error
 			want:   false,
 		},
+		{
+			name: "with intermediate responses - success",
+			responses: []*messages.DeployResponse{
+				{Hostname: "host1", Status: messages.StatusStarted},
+				{Hostname: "host1", Status: messages.StatusCompleted},
+			},
+			want: true,
+		},
+		{
+			name: "with intermediate responses - failure",
+			responses: []*messages.DeployResponse{
+				{Hostname: "host1", Status: messages.StatusStarted},
+				{Hostname: "host1", Status: messages.StatusFailed},
+			},
+			want: false,
+		},
+		{
+			name: "multiple hosts with intermediate responses",
+			responses: []*messages.DeployResponse{
+				{Hostname: "host1", Status: messages.StatusStarted},
+				{Hostname: "host2", Status: messages.StatusStarted},
+				{Hostname: "host1", Status: messages.StatusCompleted},
+				{Hostname: "host2", Status: messages.StatusCompleted},
+			},
+			want: true,
+		},
+		{
+			name: "only intermediate responses - no final",
+			responses: []*messages.DeployResponse{
+				{Hostname: "host1", Status: messages.StatusStarted},
+				{Hostname: "host1", Status: messages.StatusAccepted},
+			},
+			want: false,
+		},
 	}
 
 	for _, tc := range tests {