refactor(groupwizard): drop unreachable empty-fields branch in handleNext

.claude/TODO/INDEX.md

@@ -18,7 +18,7 @@ Severity tiers:
 - **medium**: doc drift, missing test, refactor with real cost
 - **low**: nits, minor doc fixes, stylistic improvements
 
-Total: **4 open TODOs**.
+Total: **3 open TODOs**.
 
 > **`step6`** and **`step8`** are the remaining steps from the 2026-09-30 MPNext
 > playbook audit (one PR each). `held-*` items wait on an owner decision.
@@ -39,11 +39,10 @@ _none open_
 | routing | security, drift | Step 6 — Headers, next.config, server-only, prerender + build in CI | [→](2026-09-30-step6-headers-csp-build-guards.md) |
 | routing | security, doc | Held — CSP notes for customer-deployed clones | [→](2026-09-30-held-csp-customer-deployments.md) |
 
-### Low (2)
+### Low (1)
 | Area | Tags | Title | File |
 |---|---|---|---|
 | components | security, bug | Step 8 — Address-label caps, error boundaries, tool-params decode, codegen escaping | [→](2026-09-30-step8-fork-specific-low-risk-items.md) |
-| components | refactor, missing-test | Unreachable "empty STEP_FIELDS" branch in `GroupWizard.handleNext` | [→](2026-09-13-dead-empty-fields-branch-handlenext.md) |
 
 ---
 
@@ -60,11 +59,11 @@ _none open_
 ### drift (1)
 - step6-headers-csp-build-guards — medium
 
-### missing-test (1)
-- dead-empty-fields-branch-handlenext — low
+### missing-test (0)
+_none open_
 
-### refactor (1)
-- dead-empty-fields-branch-handlenext — low
+### refactor (0)
+_none open_
 
 ### doc (1)
 - held-csp-customer-deployments — medium
@@ -78,7 +77,7 @@ _none open_
 
 | Area | Count |
 |---|---|
-| components | 2 |
+| components | 1 |
 | routing | 2 |
 | services | 0 |
 | auth | 0 |

src/app/(web)/tools/groupwizard/group-wizard.tsx

@@ -118,14 +118,9 @@ export function GroupWizard({ params, mpTimezone }: GroupWizardProps) {
   }, []);
 
   const handleNext = useCallback(async () => {
-    const fields = STEP_FIELDS[currentStep];
-    if (!fields || fields.length === 0) {
-      setCompletedSteps((prev) => new Set(prev).add(currentStep));
-      setCurrentStep((prev) => Math.min(prev + 1, WIZARD_STEPS.length - 1));
-      return;
-    }
-
-    const isValid = await form.trigger(fields as (keyof GroupWizardFormData)[]);
+    // No special case for a step without fields: `trigger([])` resolves true,
+    // and a missing entry (`undefined`) validates the whole form — fails safe.
+    const isValid = await form.trigger(STEP_FIELDS[currentStep]);
     if (isValid) {
       setCompletedSteps((prev) => new Set(prev).add(currentStep));
       setCurrentStep((prev) => Math.min(prev + 1, WIZARD_STEPS.length - 1));

src/components/group-wizard/schema.test.ts

@@ -6,6 +6,7 @@ import {
   STEP_FIELDS,
   type GroupWizardFormData,
 } from './schema';
+import { WIZARD_STEPS } from './types';
 
 /** Helper: fill all required IDs + Start_Date so schema passes base validation */
 function validBase(): GroupWizardFormData {
@@ -113,6 +114,17 @@ describe('STEP_FIELDS', () => {
     expect(Object.keys(STEP_FIELDS)).toEqual(['0', '1', '2', '3', '4', '5']);
   });
 
+  // GroupWizard.handleNext calls form.trigger(STEP_FIELDS[currentStep]) with no
+  // special case, and the last step shows Submit, not Next. So every step
+  // before Review must list fields to validate, or Next would skip validation.
+  it('every step before the Review step has fields, and only Review is empty', () => {
+    expect(Object.keys(STEP_FIELDS)).toHaveLength(WIZARD_STEPS.length);
+    WIZARD_STEPS.slice(0, -1).forEach((_, i) => {
+      expect(STEP_FIELDS[i].length).toBeGreaterThan(0);
+    });
+    expect(STEP_FIELDS[WIZARD_STEPS.length - 1]).toEqual([]);
+  });
+
   it('STEP_FIELDS[4] includes the hyphenated Secure_Check-in field name', () => {
     expect(STEP_FIELDS[4]).toContain('Secure_Check-in');
   });