fix: Rewrite activeClusterSelectionPolicy schema to remove legacy fields & handle empty policy (#1351)

## Summary
[v1.4.0 of
Cadence](https://github.com/cadence-workflow/cadence/releases/tag/v1.4.0)
introduces Active-Active Domains, which brings with it the concept of
starting workflows with a special Active Cluster Selection Policy.

However, when starting a workflow, users can specify an empty Active
Cluster Selection Policy, which the Cadence UI fails to parse and render
appropriately (#1344).

This PR fixes that by:
- Fixing the schema to account for an empty ActiveClusterSelectionPolicy
- Pulling in the latest Cadence IDL changes, including
cadence-workflow/cadence-idl#264
- This allows us to clean up the legacy active-active implementation on
our side as well

## Test plan
Ran locally.

### Before
<img width="2559" height="658" alt="Screenshot 2026-06-11 at 15 41 56"
src="https://github.com/user-attachments/assets/f11a50b4-1d36-4ad2-9d6e-a1ecdfed0b20"
/>

### After
<img width="1645" height="1186" alt="Screenshot 2026-06-12 at 14 16 29"
src="https://github.com/user-attachments/assets/cf4ea181-ffa6-432a-ae10-cdb9b336cc69"
/>

## Notes
Fixes #1344

---------

Signed-off-by: Adhitya Mamallan <adhitya.mamallan@uber.com>

Author: adhityamamallan

package.json

@@ -2,7 +2,7 @@
   "name": "cadence-web",
   "private": true,
   "config": {
-    "cadence_idl_version": "8bcf2d71101b757ee820e2d05249deec9f4dddca"
+    "cadence_idl_version": "3ee08a98cf704ed8b2cc2101abe71ab80eccf542"
   },
   "scripts": {
     "dev": "CADENCE_WEB_PORT=${CADENCE_WEB_PORT:-8088} next dev -p ${CADENCE_WEB_PORT:-8088} -H ${CADENCE_WEB_HOSTNAME:-0.0.0.0} | pino-pretty --messageKey message",

src/route-handlers/list-workflows/helpers/__tests__/get-workflow-list-item-from-execution.test.ts

@@ -71,8 +71,6 @@ describe('getWorkflowListItemFromExecution', () => {
     const execution: WorkflowExecutionInfo = {
       ...BASE_EXECUTION,
       activeClusterSelectionPolicy: {
-        strategy: 'ACTIVE_CLUSTER_SELECTION_STRATEGY_INVALID',
-        strategyConfig: 'activeClusterStickyRegionConfig',
         clusterAttribute: {
           scope: 'mock-scope',
           name: 'mock-cluster-name',

src/utils/data-formatters/schema/history-event-schema.ts

@@ -1,7 +1,6 @@
 import { z } from 'zod';
 
 import { type ActiveClusterSelectionPolicy } from '@/__generated__/proto-ts/uber/cadence/api/v1/ActiveClusterSelectionPolicy';
-import { ActiveClusterSelectionStrategy } from '@/__generated__/proto-ts/uber/cadence/api/v1/ActiveClusterSelectionStrategy';
 import { CancelExternalWorkflowExecutionFailedCause } from '@/__generated__/proto-ts/uber/cadence/api/v1/CancelExternalWorkflowExecutionFailedCause';
 import { ChildWorkflowExecutionFailedCause } from '@/__generated__/proto-ts/uber/cadence/api/v1/ChildWorkflowExecutionFailedCause';
 import { ContinueAsNewInitiator } from '@/__generated__/proto-ts/uber/cadence/api/v1/ContinueAsNewInitiator';
@@ -148,46 +147,20 @@ const clusterAttributeSchema = z.object({
   name: z.string(),
 });
 
-// TODO @adhitya.mamallan - this needs to be removed as part of active-active's redesign, once the IDL has removed them
-const activeClusterSelectionStrategySchema = z.enum([
-  ActiveClusterSelectionStrategy.ACTIVE_CLUSTER_SELECTION_STRATEGY_INVALID,
-  ActiveClusterSelectionStrategy.ACTIVE_CLUSTER_SELECTION_STRATEGY_REGION_STICKY,
-  ActiveClusterSelectionStrategy.ACTIVE_CLUSTER_SELECTION_STRATEGY_EXTERNAL_ENTITY,
-]);
-
-// The IDL still contains the strategy and strategyConfig fields, but they are absent
-// in the new active-active design. The preprocess step corrects this and allows us to
-// parse activeClusterSelectionPolicy even if the backend does not pass the deprecated fields.
-//
-// TODO @adhitya.mamallan - update this once the IDL has been updated
-const activeClusterSelectionPolicySchema = z.preprocess(
-  (data) => {
-    if (typeof data === 'object' && data !== null) {
-      const dataWithDefaults = {
-        ...data,
-        strategy:
-          'strategy' in data && data.strategy
-            ? data.strategy
-            : 'ACTIVE_CLUSTER_SELECTION_STRATEGY_INVALID',
-        strategyConfig:
-          'strategyConfig' in data && data.strategyConfig
-            ? data.strategyConfig
-            : 'activeClusterStickyRegionConfig',
-      };
-      return dataWithDefaults;
-    }
-    return data;
-  },
-  z.object({
-    clusterAttribute: clusterAttributeSchema,
-    // TODO: remove the below fields once the IDL has removed them
-    strategy: activeClusterSelectionStrategySchema,
-    strategyConfig: z.enum([
-      'activeClusterStickyRegionConfig',
-      'activeClusterExternalEntityConfig',
-    ]),
+/**
+ * In the active-active design the policy is identified solely by clusterAttribute, so a missing
+ * or malformed payload carries no policy and falls back to null instead of failing the whole
+ * history event.
+ *
+ * activeClusterSelectionPolicy and retryPolicy are the only object fields passed to StartWorkflow,
+ * but activeClusterSelectionPolicy does not validate the request input type the way retryPolicy does.
+ */
+const activeClusterSelectionPolicySchema = z
+  .object({
+    clusterAttribute: clusterAttributeSchema.nullable(),
   })
-) as z.ZodType<ActiveClusterSelectionPolicy>;
+  .nullable()
+  .catch(null) as z.ZodType<ActiveClusterSelectionPolicy | null>;
 
 const failureSchema = z.object({
   reason: z.string(),