Fix criteria validation using wrong form + fix reports page null crash

1. Evaluation submit: The requireAllCriteriaScored validation was
   querying findFirst({ roundId, isActive: true }) to get the form
   criteria, instead of using the evaluation's stored formId. If an
   admin ever re-saved the evaluation form (creating a new version
   with new criterion IDs), jurors who started evaluating before the
   re-save had scores keyed to old IDs that didn't match the new
   form. Now uses evaluation.form (the form assigned at start time).

2. Observer reports page: Two .map() calls on p.stages lacked null
   guards, causing "Cannot read properties of null (reading 'map')"
   crash. Added (p.stages || []) guards matching the pattern already
   used in CrossStageTab.

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

src/server/routers/evaluation.ts

@@ -146,6 +146,7 @@ export const evaluationRouter = router({
         where: { id },
         include: {
           assignment: true,
+          form: { select: { criteriaJson: true } },
         },
       })
 
@@ -231,11 +232,11 @@ export const evaluationRouter = router({
       }
 
       // Fix 5: requireAllCriteriaScored validation
+      // Use the form the juror was assigned (evaluation.form), NOT the current active form.
+      // If the admin re-saves the form, criterion IDs change — jurors who started before
+      // the re-save would have scores keyed to old IDs that don't match the new form.
       if (config.requireAllCriteriaScored && scoringMode === 'criteria') {
-        const evalForm = await ctx.prisma.evaluationForm.findFirst({
-          where: { roundId: round.id, isActive: true },
-          select: { criteriaJson: true },
-        })
+        const evalForm = evaluation.form
         if (evalForm?.criteriaJson) {
           const criteria = evalForm.criteriaJson as Array<{ id: string; label?: string; type?: string; required?: boolean }>
           const scorableCriteria = criteria.filter(