refactor: tech debt batch 3 — type safety + assignment router split

#5 — Replaced 55x PrismaClient | any with proper Prisma types across 8 files
- Service files: PrismaClient | any → PrismaClient, tx: any → Prisma.TransactionClient
- Fixed 4 real bugs uncovered by typing:
  - mentor-workspace.ts: wrong FK fields (mentorAssignmentId → workspaceId, role → senderRole)
  - ai-shortlist.ts: untyped string passed to CompetitionCategory enum filter
  - result-lock.ts: unknown passed where Prisma.InputJsonValue required

#9 — Split assignment.ts (2,775 lines) into 6 focused files:
  - shared.ts (93 lines) — MOVABLE_EVAL_STATUSES, buildBatchNotifications, getCandidateJurors
  - assignment-crud.ts (473 lines) — 8 core CRUD procedures
  - assignment-suggestions.ts (880 lines) — AI suggestions + job runner
  - assignment-notifications.ts (138 lines) — 2 notification procedures
  - assignment-redistribution.ts (1,162 lines) — 8 reassign/transfer procedures
  - index.ts (15 lines) — barrel export with router merge, zero frontend changes

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

src/server/services/mentor-workspace.ts

@@ -19,13 +19,13 @@ type WorkspaceResult = { success: boolean; errors?: string[] }
  * Activate a mentor workspace for a given assignment.
  */
 export async function activateWorkspace(
-  mentorAssignmentId: string,
+  workspaceId: string,
   actorId: string,
-  prisma: PrismaClient | any,
+  prisma: PrismaClient,
 ): Promise<WorkspaceResult> {
   try {
     const assignment = await prisma.mentorAssignment.findUnique({
-      where: { id: mentorAssignmentId },
+      where: { id: workspaceId },
     })
 
     if (!assignment) {
@@ -36,9 +36,9 @@ export async function activateWorkspace(
       return { success: false, errors: ['Workspace is already enabled'] }
     }
 
-    await prisma.$transaction(async (tx: any) => {
+    await prisma.$transaction(async (tx: Prisma.TransactionClient) => {
       await tx.mentorAssignment.update({
-        where: { id: mentorAssignmentId },
+        where: { id: workspaceId },
         data: {
           workspaceEnabled: true,
           workspaceOpenAt: new Date(),
@@ -49,7 +49,7 @@ export async function activateWorkspace(
         data: {
           eventType: 'mentor_workspace.activated',
           entityType: 'MentorAssignment',
-          entityId: mentorAssignmentId,
+          entityId: workspaceId,
           actorId,
           detailsJson: {
             projectId: assignment.projectId,
@@ -64,7 +64,7 @@ export async function activateWorkspace(
         userId: actorId,
         action: 'WORKSPACE_ACTIVATE',
         entityType: 'MentorAssignment',
-        entityId: mentorAssignmentId,
+        entityId: workspaceId,
         detailsJson: { projectId: assignment.projectId },
       })
     })
@@ -86,15 +86,15 @@ export async function activateWorkspace(
  */
 export async function sendMessage(
   params: {
-    mentorAssignmentId: string
+    workspaceId: string
     senderId: string
     message: string
     role: 'MENTOR_ROLE' | 'APPLICANT_ROLE' | 'ADMIN_ROLE'
   },
-  prisma: PrismaClient | any,
+  prisma: PrismaClient,
 ) {
   const assignment = await prisma.mentorAssignment.findUnique({
-    where: { id: params.mentorAssignmentId },
+    where: { id: params.workspaceId },
   })
 
   if (!assignment) {
@@ -107,11 +107,11 @@ export async function sendMessage(
 
   return prisma.mentorMessage.create({
     data: {
-      mentorAssignmentId: params.mentorAssignmentId,
+      workspaceId: params.workspaceId,
       projectId: assignment.projectId,
       senderId: params.senderId,
       message: params.message,
-      role: params.role,
+      senderRole: params.role,
     },
     include: {
       sender: { select: { id: true, name: true, email: true } },
@@ -123,11 +123,11 @@ export async function sendMessage(
  * Get messages for a workspace.
  */
 export async function getMessages(
-  mentorAssignmentId: string,
-  prisma: PrismaClient | any,
+  workspaceId: string,
+  prisma: PrismaClient,
 ) {
   return prisma.mentorMessage.findMany({
-    where: { mentorAssignmentId },
+    where: { workspaceId },
     include: {
       sender: { select: { id: true, name: true, email: true, role: true } },
     },
@@ -140,7 +140,7 @@ export async function getMessages(
  */
 export async function markRead(
   messageId: string,
-  prisma: PrismaClient | any,
+  prisma: PrismaClient,
 ): Promise<void> {
   await prisma.mentorMessage.update({
     where: { id: messageId },
@@ -155,7 +155,7 @@ export async function markRead(
  */
 export async function uploadFile(
   params: {
-    mentorAssignmentId: string
+    workspaceId: string
     uploadedByUserId: string
     fileName: string
     mimeType: string
@@ -164,10 +164,10 @@ export async function uploadFile(
     objectKey: string
     description?: string
   },
-  prisma: PrismaClient | any,
+  prisma: PrismaClient,
 ) {
   const assignment = await prisma.mentorAssignment.findUnique({
-    where: { id: params.mentorAssignmentId },
+    where: { id: params.workspaceId },
   })
 
   if (!assignment) {
@@ -180,7 +180,7 @@ export async function uploadFile(
 
   return prisma.mentorFile.create({
     data: {
-      mentorAssignmentId: params.mentorAssignmentId,
+      mentorAssignmentId: params.workspaceId,
       uploadedByUserId: params.uploadedByUserId,
       fileName: params.fileName,
       mimeType: params.mimeType,
@@ -205,7 +205,7 @@ export async function addFileComment(
     content: string
     parentCommentId?: string
   },
-  prisma: PrismaClient | any,
+  prisma: PrismaClient,
 ) {
   return prisma.mentorFileComment.create({
     data: {
@@ -233,7 +233,7 @@ export async function promoteFile(
     slotKey: string
     promotedById: string
   },
-  prisma: PrismaClient | any,
+  prisma: PrismaClient,
 ): Promise<{ success: boolean; errors?: string[] }> {
   try {
     const file = await prisma.mentorFile.findUnique({
@@ -251,7 +251,7 @@ export async function promoteFile(
       return { success: false, errors: ['File is already promoted'] }
     }
 
-    await prisma.$transaction(async (tx: any) => {
+    await prisma.$transaction(async (tx: Prisma.TransactionClient) => {
       // Mark file as promoted
       await tx.mentorFile.update({
         where: { id: params.mentorFileId },