refactor: tech debt batch 2 — drop dead models, stale columns, schema cleanup

Schema:
- Drop 4 dead models: OverrideAction, NotificationPolicy, AssignmentException, AdvancementRule
- Drop 2 dead enums: OverrideReasonCode, AdvancementRuleType
- Drop 3 stale columns: Project.roundId, ConflictOfInterest.roundId, Evaluation.version
- Remove 3 back-relation fields from User, Assignment, Round

Code:
- Fix 6 COI queries in assignment.ts + 1 in juror-reassignment.ts
  (roundId filter → assignment.roundId after column drop)
- Remove orphaned Project.roundId write in project.ts createProject
- Remove advancementRules include from round.ts getById
- Remove AdvancementRule from RoundWithRelations type
- Clean up seed.ts (remove advancement rule seeding)
- Clean up tests/helpers.ts (remove dead model cleanup)
- Add TODO comments on user delete mutations (FK violation risk)

Migration: 20260308000000_drop_dead_models_and_stale_columns

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

src/server/routers/assignment.ts

@@ -119,7 +119,7 @@ async function runAIAssignmentJob(jobId: string, roundId: string, userId: string
     // Query COI records for this round to exclude conflicted juror-project pairs
     const coiRecords = await prisma.conflictOfInterest.findMany({
       where: {
-        roundId,
+        assignment: { roundId },
         hasConflict: true,
       },
       select: { userId: true, projectId: true },
@@ -1665,7 +1665,7 @@ export const assignmentRouter = router({
       for (const a of existingAssignments) currentLoads.set(a.userId, (currentLoads.get(a.userId) ?? 0) + 1)
 
       const coiRecords = await ctx.prisma.conflictOfInterest.findMany({
-        where: { roundId: input.roundId, hasConflict: true, userId: { in: candidateIds } },
+        where: { assignment: { roundId: input.roundId }, hasConflict: true, userId: { in: candidateIds } },
         select: { userId: true, projectId: true },
       })
       const coiPairs = new Set(coiRecords.map((c) => `${c.userId}:${c.projectId}`))
@@ -1911,7 +1911,7 @@ export const assignmentRouter = router({
 
       const coiRecords = await ctx.prisma.conflictOfInterest.findMany({
         where: {
-          roundId: input.roundId,
+          assignment: { roundId: input.roundId },
           hasConflict: true,
           userId: { in: candidateIds },
         },
@@ -2026,7 +2026,7 @@ export const assignmentRouter = router({
 
       const coiRecords = await ctx.prisma.conflictOfInterest.findMany({
         where: {
-          roundId: input.roundId,
+          assignment: { roundId: input.roundId },
           hasConflict: true,
           userId: { in: destinationIds },
         },
@@ -2367,7 +2367,7 @@ export const assignmentRouter = router({
 
       const coiRecords = await ctx.prisma.conflictOfInterest.findMany({
         where: {
-          roundId: input.roundId,
+          assignment: { roundId: input.roundId },
           hasConflict: true,
           userId: { in: candidateIds },
         },

src/server/routers/project.ts

@@ -638,10 +638,6 @@ export const projectRouter = router({
         })
 
         if (input.roundId) {
-          await tx.project.update({
-            where: { id: created.id },
-            data: { roundId: input.roundId },
-          })
           await tx.projectRoundState.create({
             data: {
               projectId: created.id,

src/server/routers/round.ts

@@ -120,7 +120,6 @@ export const roundRouter = router({
           submissionWindow: {
             include: { fileRequirements: true },
           },
-          advancementRules: { orderBy: { sortOrder: 'asc' } },
           visibleSubmissionWindows: {
             include: { submissionWindow: true },
           },

src/server/routers/user.ts

@@ -206,7 +206,10 @@ export const userRouter = router({
         })
       }
 
-      // Delete user
+      // TODO: This delete will fail with a FK violation for any user with activity
+      // (COI declarations, mentor assignments, messages, evaluations, etc.).
+      // A proper purge flow with pre-deletion cleanup or soft-delete is needed
+      // before hard-delete can work reliably for active users.
       await ctx.prisma.user.delete({
         where: { id: ctx.user.id },
       })
@@ -657,6 +660,10 @@ export const userRouter = router({
         select: { email: true },
       })
 
+      // TODO: This delete will fail with a FK violation for any user with activity
+      // (COI declarations, mentor assignments, messages, evaluations, etc.).
+      // A proper purge flow with pre-deletion cleanup or soft-delete is needed
+      // before hard-delete can work reliably for active users.
       const user = await ctx.prisma.user.delete({
         where: { id: input.id },
       })

src/server/services/juror-reassignment.ts

@@ -357,7 +357,7 @@ export async function reassignDroppedJurorAssignments(params: {
 
   const coiRecords = await prisma.conflictOfInterest.findMany({
     where: {
-      roundId: params.roundId,
+      assignment: { roundId: params.roundId },
       hasConflict: true,
       userId: { in: candidateIds },
     },

src/types/competition.ts

@@ -5,7 +5,6 @@ import type {
   JuryGroupMember,
   SubmissionWindow,
   SubmissionFileRequirement,
-  AdvancementRule,
   RoundSubmissionVisibility,
   ProjectRoundState,
   DeliberationSession,
@@ -36,7 +35,6 @@ export type RoundSummary = Pick<
 export type RoundWithRelations = Round & {
   juryGroup: (JuryGroup & { members: JuryGroupMember[] }) | null
   submissionWindow: (SubmissionWindow & { fileRequirements: SubmissionFileRequirement[] }) | null
-  advancementRules: AdvancementRule[]
   visibleSubmissionWindows: (RoundSubmissionVisibility & { submissionWindow: SubmissionWindow })[]
   _count?: { projectRoundStates: number; assignments: number }
 }