Fix pipeline edit crash: merge defaults with DB configJson

The DB configJson uses different field names than wizard types expect
(e.g., deterministic.rules vs rules, votingEnabled vs juryVotingEnabled).
The ?? operator only guards null/undefined, but configJson is {} (truthy),
so defaults never applied. This caused config.rules.map() to crash with
"Cannot read properties of undefined (reading 'map')".

Fix: spread defaults first then overlay DB values, and add defensive ??
fallbacks in all section components for potentially undefined properties.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/admin/pipeline/sections/assignment-section.tsx

@@ -32,7 +32,7 @@ export function AssignmentSection({ config, onChange, isActive }: AssignmentSect
             type="number"
             min={1}
             max={20}
-            value={config.requiredReviews}
+            value={config.requiredReviews ?? 3}
             disabled={isActive}
             onChange={(e) =>
               updateConfig({ requiredReviews: parseInt(e.target.value) || 3 })
@@ -49,7 +49,7 @@ export function AssignmentSection({ config, onChange, isActive }: AssignmentSect
             type="number"
             min={1}
             max={100}
-            value={config.maxLoadPerJuror}
+            value={config.maxLoadPerJuror ?? 20}
             disabled={isActive}
             onChange={(e) =>
               updateConfig({ maxLoadPerJuror: parseInt(e.target.value) || 20 })
@@ -66,7 +66,7 @@ export function AssignmentSection({ config, onChange, isActive }: AssignmentSect
             type="number"
             min={0}
             max={50}
-            value={config.minLoadPerJuror}
+            value={config.minLoadPerJuror ?? 5}
             disabled={isActive}
             onChange={(e) =>
               updateConfig({ minLoadPerJuror: parseInt(e.target.value) || 5 })
@@ -78,7 +78,7 @@ export function AssignmentSection({ config, onChange, isActive }: AssignmentSect
         </div>
       </div>
 
-      {config.minLoadPerJuror > config.maxLoadPerJuror && (
+      {(config.minLoadPerJuror ?? 0) > (config.maxLoadPerJuror ?? 20) && (
         <p className="text-sm text-destructive">
           Min load per juror cannot exceed max load per juror.
         </p>
@@ -92,7 +92,7 @@ export function AssignmentSection({ config, onChange, isActive }: AssignmentSect
           </p>
         </div>
         <Switch
-          checked={config.availabilityWeighting}
+          checked={config.availabilityWeighting ?? true}
           onCheckedChange={(checked) =>
             updateConfig({ availabilityWeighting: checked })
           }
@@ -103,7 +103,7 @@ export function AssignmentSection({ config, onChange, isActive }: AssignmentSect
       <div className="space-y-2">
         <Label>Overflow Policy</Label>
         <Select
-          value={config.overflowPolicy}
+          value={config.overflowPolicy ?? 'queue'}
           onValueChange={(value) =>
             updateConfig({
               overflowPolicy: value as EvaluationConfig['overflowPolicy'],