Fix build errors: add missing Prisma models/fields and resolve TypeScript type errors

Schema: Add 11 new models (RoundTemplate, MentorNote, MentorMilestone,
MentorMilestoneCompletion, EvaluationDiscussion, DiscussionComment,
Message, MessageRecipient, MessageTemplate, Webhook, WebhookDelivery,
DigestLog) and missing fields on existing models (Project.isDraft,
ProjectFile.version, LiveVotingSession.allowAudienceVotes, User.digestFrequency,
AuditLog.sessionId, MentorAssignment.completionStatus, etc).
Add AUDIT_CONFIG/LOCALIZATION/DIGEST/ANALYTICS enum values.

Code: Fix implicit any types, route type casts, enum casts, null safety,
composite key handling, and relation field names across 11 source files.

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

src/server/routers/mentor.ts

@@ -981,9 +981,9 @@ export const mentorRouter = router({
       })
       const myAssignmentIds = new Set(myAssignments.map((a) => a.id))
 
-      return milestones.map((milestone) => ({
+      return milestones.map((milestone: typeof milestones[number]) => ({
         ...milestone,
-        myCompletions: milestone.completions.filter((c) =>
+        myCompletions: milestone.completions.filter((c: { mentorAssignmentId: string }) =>
           myAssignmentIds.has(c.mentorAssignmentId)
         ),
       }))
@@ -1036,7 +1036,7 @@ export const mentorRouter = router({
       const completedMilestones = await ctx.prisma.mentorMilestoneCompletion.findMany({
         where: {
           mentorAssignmentId: input.mentorAssignmentId,
-          milestoneId: { in: requiredMilestones.map((m) => m.id) },
+          milestoneId: { in: requiredMilestones.map((m: { id: string }) => m.id) },
         },
         select: { milestoneId: true },
       })
@@ -1057,7 +1057,7 @@ export const mentorRouter = router({
           userId: ctx.user.id,
           action: 'COMPLETE_MILESTONE',
           entityType: 'MentorMilestoneCompletion',
-          entityId: completion.id,
+          entityId: `${completion.milestoneId}_${completion.mentorAssignmentId}`,
           detailsJson: {
             milestoneId: input.milestoneId,
             mentorAssignmentId: input.mentorAssignmentId,
@@ -1243,7 +1243,7 @@ export const mentorRouter = router({
           mentor: { select: { id: true, name: true, email: true } },
           project: { select: { id: true, title: true } },
           notes: { select: { id: true } },
-          milestoneCompletions: { select: { id: true } },
+          milestoneCompletions: { select: { milestoneId: true } },
         },
       })