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/live-finals-section.tsx

@@ -33,7 +33,7 @@ export function LiveFinalsSection({ config, onChange, isActive }: LiveFinalsSect
           </p>
         </div>
         <Switch
-          checked={config.juryVotingEnabled}
+          checked={config.juryVotingEnabled ?? true}
           onCheckedChange={(checked) =>
             updateConfig({ juryVotingEnabled: checked })
           }
@@ -50,7 +50,7 @@ export function LiveFinalsSection({ config, onChange, isActive }: LiveFinalsSect
             </p>
           </div>
           <Switch
-            checked={config.audienceVotingEnabled}
+            checked={config.audienceVotingEnabled ?? false}
             onCheckedChange={(checked) =>
               updateConfig({ audienceVotingEnabled: checked })
             }
@@ -58,13 +58,13 @@ export function LiveFinalsSection({ config, onChange, isActive }: LiveFinalsSect
           />
         </div>
 
-        {config.audienceVotingEnabled && (
+        {(config.audienceVotingEnabled ?? false) && (
           <div className="pl-4 border-l-2 border-muted space-y-3">
             <div className="space-y-2">
               <Label className="text-xs">Audience Vote Weight</Label>
               <div className="flex items-center gap-3">
                 <Slider
-                  value={[config.audienceVoteWeight * 100]}
+                  value={[(config.audienceVoteWeight ?? 0) * 100]}
                   onValueChange={([v]) =>
                     updateConfig({ audienceVoteWeight: v / 100 })
                   }
@@ -74,7 +74,7 @@ export function LiveFinalsSection({ config, onChange, isActive }: LiveFinalsSect
                   className="flex-1"
                 />
                 <span className="text-xs font-mono w-10 text-right">
-                  {Math.round(config.audienceVoteWeight * 100)}%
+                  {Math.round((config.audienceVoteWeight ?? 0) * 100)}%
                 </span>
               </div>
               <p className="text-xs text-muted-foreground">
@@ -88,7 +88,7 @@ export function LiveFinalsSection({ config, onChange, isActive }: LiveFinalsSect
       <div className="space-y-2">
         <Label>Cohort Setup Mode</Label>
         <Select
-          value={config.cohortSetupMode}
+          value={config.cohortSetupMode ?? 'manual'}
           onValueChange={(value) =>
             updateConfig({
               cohortSetupMode: value as LiveFinalConfig['cohortSetupMode'],
@@ -113,7 +113,7 @@ export function LiveFinalsSection({ config, onChange, isActive }: LiveFinalsSect
       <div className="space-y-2">
         <Label>Result Reveal Policy</Label>
         <Select
-          value={config.revealPolicy}
+          value={config.revealPolicy ?? 'ceremony'}
           onValueChange={(value) =>
             updateConfig({
               revealPolicy: value as LiveFinalConfig['revealPolicy'],