feat: introduce conditional steps and branching logic to the experiment wizard and designer, along with new core and WoZ plugins.

src/components/experiments/designer/state/validators.ts

@@ -53,6 +53,7 @@ export interface ValidationResult {
 // Parallel/conditional/loop execution happens at the ACTION level, not step level
 const VALID_STEP_TYPES: StepType[] = [
   "sequential",
+  "conditional",
 ];
 const VALID_TRIGGER_TYPES: TriggerType[] = [
   "trial_start",
@@ -391,6 +392,34 @@ export function validateParameters(
             }
             break;
 
+          case "array":
+            if (!Array.isArray(value)) {
+              issues.push({
+                severity: "error",
+                message: `Parameter '${paramDef.name}' must be a list/array`,
+                category: "parameter",
+                field,
+                stepId,
+                actionId,
+                suggestion: "Enter a list of values",
+              });
+            }
+            break;
+
+          case "json":
+            if (typeof value !== "object" || value === null) {
+              issues.push({
+                severity: "error",
+                message: `Parameter '${paramDef.name}' must be a valid object`,
+                category: "parameter",
+                field,
+                stepId,
+                actionId,
+                suggestion: "Enter a valid JSON object",
+              });
+            }
+            break;
+
           default:
             // Unknown parameter type
             issues.push({