feat(react-sdk): return discriminated union from safeSchemaToJsonSchema

Change `safeSchemaToJsonSchema` to return a discriminated union result object instead of `JSONSchema7 | undefined`. This makes error handling explicit and allows callers to decide how strictly to handle failures.

- Introduce `SafeSchemaToJsonSchemaResult` type with `success` discriminator
- Return a structured error when no schema is provided
- Preserve console error logging while surfacing the error message
- Keep `schemaToJsonSchema` behavior unchanged, still delegating to `toJsonSchema.sync` for standard schemas

Author: CharlieHelps

react-sdk/src/util/schema.ts

@@ -177,22 +177,48 @@ export function schemaToJsonSchema(schema: Schema): JSONSchema7 {
   return toJsonSchema.sync(schema) as JSONSchema7;
 }
 
+export type SafeSchemaToJsonSchemaResult =
+  | { schema: JSONSchema7; success: true }
+  | { schema: undefined; success: false; error: string };
+
 /**
- * Safely converts a schema to JSON Schema, returning undefined for invalid inputs.
+ * Safely converts a schema to JSON Schema.
+ *
+ * Instead of throwing on conversion errors, this returns a discriminated union
+ * so callers can decide how strictly to handle failures.
  * @param schema - The schema to convert (may be undefined)
- * @returns The JSON Schema representation, or undefined if conversion fails
+ * @returns A result object containing the converted schema on success, or an
+ * error message on failure
  */
 export function safeSchemaToJsonSchema(
   schema: Schema | undefined | null,
-): JSONSchema7 | undefined {
+): SafeSchemaToJsonSchemaResult {
   if (!schema) {
-    return undefined;
+    return {
+      schema: undefined,
+      success: false,
+      error: "No schema provided",
+    };
   }
 
   try {
-    return schemaToJsonSchema(schema);
+    const jsonSchema = schemaToJsonSchema(schema);
+    return {
+      schema: jsonSchema,
+      success: true,
+    };
   } catch (error) {
+    const message =
+      error instanceof Error
+        ? error.message
+        : "Unknown error converting schema to JSON Schema";
+
     console.error("Error converting schema to JSON Schema:", error);
-    return undefined;
+
+    return {
+      schema: undefined,
+      success: false,
+      error: message,
+    };
   }
 }