platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/transportcfg/runtime_helpers_test.go

@@ -0,0 +1,67 @@
+package transportcfg
+
+import "testing"
+
+func TestBackendUnitSingBoxUsesInstanceTemplateByDefault(t *testing.T) {
+	client := Client{
+		ID:   "sg-realnetns",
+		Kind: KindSingBox,
+	}
+	got := BackendUnit(client)
+	if got != "singbox@sg-realnetns.service" {
+		t.Fatalf("unexpected singbox unit: %q", got)
+	}
+}
+
+func TestBackendUnitSingBoxTemplateConfigExpandsInstance(t *testing.T) {
+	client := Client{
+		ID:   "sg-1",
+		Kind: KindSingBox,
+		Config: map[string]any{
+			"unit": "singbox@.service",
+		},
+	}
+	got := BackendUnit(client)
+	if got != "singbox@sg-1.service" {
+		t.Fatalf("unexpected template unit: %q", got)
+	}
+}
+
+func TestBackendUnitSingBoxKeepsExplicitNonTemplateUnit(t *testing.T) {
+	client := Client{
+		ID:   "sg-realnetns",
+		Kind: KindSingBox,
+		Config: map[string]any{
+			"unit": "custom-singbox.service",
+		},
+	}
+	got := BackendUnit(client)
+	if got != "custom-singbox.service" {
+		t.Fatalf("unexpected custom unit: %q", got)
+	}
+}
+
+func TestBackendUnitNonSingBoxUnchanged(t *testing.T) {
+	client := Client{
+		ID:   "dn-1",
+		Kind: KindDNSTT,
+		Config: map[string]any{
+			"unit": "dnstt-custom.service",
+		},
+	}
+	got := BackendUnit(client)
+	if got != "dnstt-custom.service" {
+		t.Fatalf("unexpected non-singbox unit: %q", got)
+	}
+}
+
+func TestBackendUnitSingBoxSanitizesInstanceID(t *testing.T) {
+	client := Client{
+		ID:   " SG Real/NetNS ",
+		Kind: KindSingBox,
+	}
+	got := BackendUnit(client)
+	if got != "singbox@sg-real-netns.service" {
+		t.Fatalf("unexpected sanitized singbox unit: %q", got)
+	}
+}