feat: auto-create/sync VisaApplication on attendee writes

confirm and adminConfirm now create REQUESTED VisaApplication rows for
every attendee with needsVisa=true, in the same Prisma transaction as
the AttendingMember inserts. editAttendees was extended into a fully
diff-aware sync: existing attendees whose needsVisa flips on get a new
VisaApp; flipping off deletes it; staying true preserves the row (and
its status / notes / dates). Removed attendees cascade automatically
via the FK.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/server/routers/finalist.ts

@@ -327,19 +327,31 @@ export const finalistRouter = router({
         }
       }
 
-      await ctx.prisma.$transaction([
-        ctx.prisma.finalistConfirmation.update({
+      await ctx.prisma.$transaction(async (tx) => {
+        await tx.finalistConfirmation.update({
           where: { id: confirmation.id },
           data: { status: 'CONFIRMED', confirmedAt: new Date() },
-        }),
-        ctx.prisma.attendingMember.createMany({
+        })
+        await tx.attendingMember.createMany({
           data: input.attendingUserIds.map((userId) => ({
             confirmationId: confirmation.id,
             userId,
             needsVisa: input.visaFlags[userId] ?? false,
           })),
-        }),
-      ])
+        })
+        const visaUsers = input.attendingUserIds.filter(
+          (uid) => input.visaFlags[uid] === true,
+        )
+        if (visaUsers.length > 0) {
+          const created = await tx.attendingMember.findMany({
+            where: { confirmationId: confirmation.id, userId: { in: visaUsers } },
+            select: { id: true },
+          })
+          await tx.visaApplication.createMany({
+            data: created.map((m) => ({ attendingMemberId: m.id, status: 'REQUESTED' })),
+          })
+        }
+      })
       await logAudit({
         prisma: ctx.prisma,
         action: 'FINALIST_CONFIRMED',
@@ -469,19 +481,31 @@ export const finalistRouter = router({
         }
       }
 
-      await ctx.prisma.$transaction([
-        ctx.prisma.finalistConfirmation.update({
+      await ctx.prisma.$transaction(async (tx) => {
+        await tx.finalistConfirmation.update({
           where: { id: confirmation.id },
           data: { status: 'CONFIRMED', confirmedAt: new Date() },
-        }),
-        ctx.prisma.attendingMember.createMany({
+        })
+        await tx.attendingMember.createMany({
           data: input.attendingUserIds.map((userId) => ({
             confirmationId: confirmation.id,
             userId,
             needsVisa: input.visaFlags[userId] ?? false,
           })),
-        }),
-      ])
+        })
+        const visaUsers = input.attendingUserIds.filter(
+          (uid) => input.visaFlags[uid] === true,
+        )
+        if (visaUsers.length > 0) {
+          const created = await tx.attendingMember.findMany({
+            where: { confirmationId: confirmation.id, userId: { in: visaUsers } },
+            select: { id: true },
+          })
+          await tx.visaApplication.createMany({
+            data: created.map((m) => ({ attendingMemberId: m.id, status: 'REQUESTED' })),
+          })
+        }
+      })
       await logAudit({
         prisma: ctx.prisma,
         userId: ctx.user.id,
@@ -916,7 +940,14 @@ export const finalistRouter = router({
               teamMembers: { select: { userId: true, role: true } },
             },
           },
-          attendingMembers: { select: { id: true, userId: true } },
+          attendingMembers: {
+            select: {
+              id: true,
+              userId: true,
+              needsVisa: true,
+              visaApplication: { select: { id: true } },
+            },
+          },
         },
       })
 
@@ -993,32 +1024,55 @@ export const finalistRouter = router({
       const toCreate = input.attendingUserIds.filter((id) => !existingByUser.has(id))
       const toUpdate = input.attendingUserIds.filter((id) => existingByUser.has(id))
 
-      await ctx.prisma.$transaction([
-        ...(toDelete.length > 0
-          ? [
-              ctx.prisma.attendingMember.deleteMany({
-                where: { id: { in: toDelete.map((m) => m.id) } },
-              }),
-            ]
-          : []),
-        ...toUpdate.map((userId) =>
-          ctx.prisma.attendingMember.update({
-            where: { id: existingByUser.get(userId)!.id },
-            data: { needsVisa: input.visaFlags[userId] ?? false },
-          }),
-        ),
-        ...(toCreate.length > 0
-          ? [
-              ctx.prisma.attendingMember.createMany({
-                data: toCreate.map((userId) => ({
-                  confirmationId: confirmation.id,
-                  userId,
-                  needsVisa: input.visaFlags[userId] ?? false,
-                })),
-              }),
-            ]
-          : []),
-      ])
+      await ctx.prisma.$transaction(async (tx) => {
+        if (toDelete.length > 0) {
+          // FK cascade removes any VisaApplication rows tied to deleted attendees
+          await tx.attendingMember.deleteMany({
+            where: { id: { in: toDelete.map((m) => m.id) } },
+          })
+        }
+
+        // Diff visa flips for users that stay
+        const visaToDelete: string[] = []
+        for (const userId of toUpdate) {
+          const existing = existingByUser.get(userId)!
+          const wantsVisa = input.visaFlags[userId] === true
+          await tx.attendingMember.update({
+            where: { id: existing.id },
+            data: { needsVisa: wantsVisa },
+          })
+          if (existing.visaApplication && !wantsVisa) {
+            visaToDelete.push(existing.visaApplication.id)
+          } else if (!existing.visaApplication && wantsVisa) {
+            await tx.visaApplication.create({
+              data: { attendingMemberId: existing.id, status: 'REQUESTED' },
+            })
+          }
+        }
+        if (visaToDelete.length > 0) {
+          await tx.visaApplication.deleteMany({ where: { id: { in: visaToDelete } } })
+        }
+
+        if (toCreate.length > 0) {
+          await tx.attendingMember.createMany({
+            data: toCreate.map((userId) => ({
+              confirmationId: confirmation.id,
+              userId,
+              needsVisa: input.visaFlags[userId] ?? false,
+            })),
+          })
+          const newVisaUsers = toCreate.filter((id) => input.visaFlags[id] === true)
+          if (newVisaUsers.length > 0) {
+            const created = await tx.attendingMember.findMany({
+              where: { confirmationId: confirmation.id, userId: { in: newVisaUsers } },
+              select: { id: true },
+            })
+            await tx.visaApplication.createMany({
+              data: created.map((m) => ({ attendingMemberId: m.id, status: 'REQUESTED' })),
+            })
+          }
+        }
+      })
 
       await logAudit({
         prisma: ctx.prisma,