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/status_test.go

@@ -253,22 +253,47 @@ func TestGetServiceStatus_IgnoreSkipsDrift(t *testing.T) {
 }
 
 func TestSplitContainerName(t *testing.T) {
+	known := map[string]bool{
+		"metacrypt": true,
+		"mc-proxy":  true,
+		"mcr":       true,
+	}
 	tests := []struct {
 		name    string
 		service string
 		comp    string
 	}{
 		{"metacrypt-api", "metacrypt", "api"},
-		{"metacrypt-web-ui", "metacrypt", "web-ui"},
+		{"metacrypt-web", "metacrypt", "web"},
+		{"mc-proxy", "mc-proxy", "mc-proxy"},
+		{"mcr-api", "mcr", "api"},
 		{"standalone", "standalone", "standalone"},
+		{"unknown-thing", "unknown", "thing"},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			svc, comp := splitContainerName(tt.name)
+			svc, comp := SplitContainerName(tt.name, known)
 			if svc != tt.service || comp != tt.comp {
-				t.Fatalf("splitContainerName(%q) = (%q, %q), want (%q, %q)",
+				t.Fatalf("SplitContainerName(%q) = (%q, %q), want (%q, %q)",
 					tt.name, svc, comp, tt.service, tt.comp)
 			}
 		})
 	}
 }
+
+func TestContainerNameFor(t *testing.T) {
+	tests := []struct {
+		service, component, want string
+	}{
+		{"metacrypt", "api", "metacrypt-api"},
+		{"mc-proxy", "mc-proxy", "mc-proxy"},
+		{"mcr", "web", "mcr-web"},
+	}
+	for _, tt := range tests {
+		got := ContainerNameFor(tt.service, tt.component)
+		if got != tt.want {
+			t.Fatalf("ContainerNameFor(%q, %q) = %q, want %q",
+				tt.service, tt.component, got, tt.want)
+		}
+	}
+}