Fix multi-click submit bug and add draft submit indicator on juror dashboard

- Initialize slider values to midpoint so visual matches stored value
  (root cause: sliders appeared filled but criteriaValues was undefined)
- Use mutateAsync for submit to properly await and prevent double-clicks
- Add startMutation.isPending to submit button disabled state
- Add error toast in evaluation-form.tsx catch block (was silent)
- Show "Ready to submit" badge and "Review & Submit" button for drafts
  on juror dashboard

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

src/app/(jury)/jury/competitions/[roundId]/projects/[projectId]/evaluate/page.tsx

@@ -173,6 +173,24 @@ export default function JuryEvaluatePage({ params: paramsPromise }: PageProps) {
     }
   })
 
+  // Initialize numeric criteria with midpoint values so slider visual matches stored value.
+  const criteriaInitializedRef = useRef(false)
+  useEffect(() => {
+    if (criteriaInitializedRef.current || criteria.length === 0) return
+    if (existingEvaluation?.criterionScoresJson) return
+    criteriaInitializedRef.current = true
+
+    const defaults: Record<string, number | boolean | string> = {}
+    for (const c of criteria) {
+      if (c.type === 'numeric') {
+        defaults[c.id] = Math.ceil((c.minScore + c.maxScore) / 2)
+      }
+    }
+    if (Object.keys(defaults).length > 0) {
+      setCriteriaValues((prev) => ({ ...defaults, ...prev }))
+    }
+  }, [criteria, existingEvaluation?.criterionScoresJson])
+
   // Build current form data for autosave
   const buildSavePayload = useCallback(() => {
     return {
@@ -370,13 +388,17 @@ export default function JuryEvaluatePage({ params: paramsPromise }: PageProps) {
       }
     }
 
-    submitMutation.mutate({
-      id: evaluationId,
-      criterionScoresJson: scoringMode === 'criteria' ? criteriaValues : {},
-      globalScore: scoringMode === 'global' ? parseInt(globalScore, 10) : computedGlobalScore,
-      binaryDecision: scoringMode === 'binary' ? binaryDecision === 'accept' : true,
-      feedbackText: feedbackText || 'No feedback provided',
-    })
+    try {
+      await submitMutation.mutateAsync({
+        id: evaluationId,
+        criterionScoresJson: scoringMode === 'criteria' ? criteriaValues : {},
+        globalScore: scoringMode === 'global' ? parseInt(globalScore, 10) : computedGlobalScore,
+        binaryDecision: scoringMode === 'binary' ? binaryDecision === 'accept' : true,
+        feedbackText: feedbackText || 'No feedback provided',
+      })
+    } catch {
+      // Error toast already handled by onError callback
+    }
   }
 
   if (!round || !project) {
@@ -840,7 +862,7 @@ export default function JuryEvaluatePage({ params: paramsPromise }: PageProps) {
           </Button>
           <Button
             onClick={handleSubmit}
-            disabled={submitMutation.isPending || autosaveMutation.isPending}
+            disabled={submitMutation.isPending || autosaveMutation.isPending || startMutation.isPending}
             className="bg-brand-blue hover:bg-brand-blue-light"
           >
             <Send className="mr-2 h-4 w-4" />