Fix container name handling for hyphenated service names

Extract ContainerNameFor and SplitContainerName into names.go.
ContainerNameFor handles single-component services where service
name equals component name (e.g., mc-proxy → "mc-proxy" not
"mc-proxy-mc-proxy"). SplitContainerName checks known services
from the registry before falling back to naive split on "-", fixing
mc-proxy being misidentified as service "mc" component "proxy".

Also fixes podman ps JSON parsing (Command field is []string not
string) found during deployment.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/agent/names.go

@@ -0,0 +1,34 @@
+package agent
+
+import "strings"
+
+// ContainerNameFor returns the expected container name for a service and
+// component. For single-component services where the component name equals
+// the service name, the container name is just the service name (e.g.,
+// "mc-proxy" not "mc-proxy-mc-proxy").
+func ContainerNameFor(service, component string) string {
+	if service == component {
+		return service
+	}
+	return service + "-" + component
+}
+
+// SplitContainerName splits a container name into service and component parts.
+// It checks known service names first to handle names like "mc-proxy" where a
+// naive split on "-" would produce the wrong result. If no known service
+// matches, it falls back to splitting on the first "-".
+func SplitContainerName(name string, knownServices map[string]bool) (service, component string) {
+	if knownServices[name] {
+		return name, name
+	}
+	for svc := range knownServices {
+		prefix := svc + "-"
+		if strings.HasPrefix(name, prefix) && len(name) > len(prefix) {
+			return svc, name[len(prefix):]
+		}
+	}
+	if i := strings.Index(name, "-"); i >= 0 {
+		return name[:i], name[i+1:]
+	}
+	return name, name
+}