Add full editing for client proofing links

lib/proofSessions.ts

@@ -134,7 +134,6 @@ export const sessionInputSchema = z.object({
 export type SessionInput = z.infer<typeof sessionInputSchema>;
 
 export const sessionPatchSchema = sessionInputSchema
-  .omit({ albumId: true })
   .partial()
   .extend({
     /** Unlock a submitted selection so the client can change it again. */
@@ -295,6 +294,18 @@ export async function updateSession(id: string, patch: SessionPatch): Promise<Pr
       }
     }
 
+    if (patch.albumId !== undefined && patch.albumId !== session.albumId) {
+      session.albumId = patch.albumId;
+    
+      // Picks from the previous album are no longer meaningful.
+      session.selection = [];
+      delete session.updatedAt;
+      delete session.submittedAt;
+    
+      // A changed album starts fresh from the client's perspective.
+      session.downloadsUsed = 0;
+    }
+
     if (patch.clientName !== undefined) session.clientName = patch.clientName;
     if (patch.download !== undefined) session.download = patch.download;
     // `null` clears, `undefined` leaves alone.