tasks: assign a task to a specific person

Backend: add tasks.assignee_user_id (nullable, fk user) + migration; persist
it through create/update and surface tasks to the assigned person in listTasks.

Frontend: New Task dialog gains a three-way Assignee control
(Myself / Department / Person) with a provider picker from /api/staff/providers;
task card + detail show the assignee's name when set.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/db/schema/tasks.ts

@@ -25,6 +25,11 @@ export const tasks = pgTable(
     // The department (member role) a task is assigned to, e.g. "reception".
     // Null means a personal task belonging to its creator. Drives who sees it.
     assigneeRole: text("assignee_role"),
+    // A specific person the task is assigned to. Null when assigned to a
+    // department or kept personal. The assignee display name lives in `assignee`.
+    assigneeUserId: text("assignee_user_id").references(() => user.id, {
+      onDelete: "set null",
+    }),
     due: text("due").notNull().default("No due date"),
     priority: text("priority").$type<TaskPriority>().notNull(),
     // Board column: todo | in_progress | done. Kept in sync with `done`

backend/src/lib/task-validation.ts

@@ -15,6 +15,7 @@ export const taskInputSchema = z.object({
   title: z.string().trim().min(1, "A task subject is required.").max(200),
   assignee: z.string().trim().max(200).default("Unassigned"),
   assigneeRole: z.enum(TASK_DEPARTMENTS).nullish(),
+  assigneeUserId: z.string().trim().max(120).nullish(),
   due: z.string().trim().max(120).default("No due date"),
   priority: z.enum(["high", "medium", "low"]).default("medium"),
   status: z.enum(["todo", "in_progress", "done"]).default("todo"),

backend/src/services/tasks.ts

@@ -24,6 +24,7 @@ function toTask(row: TaskRow): Task {
     title: row.title,
     assignee: row.assignee,
     assigneeRole: row.assigneeRole,
+    assigneeUserId: row.assigneeUserId,
     due: row.due,
     priority: row.priority,
     status: row.status,
@@ -48,7 +49,11 @@ export async function listTasks(
 
   let where = eq(tasks.organizationId, orgId);
   if (!isAdmin) {
-    const visible = [eq(tasks.createdBy, viewer.userId)];
+    const visible = [
+      eq(tasks.createdBy, viewer.userId),
+      // Tasks assigned to this person specifically.
+      eq(tasks.assigneeUserId, viewer.userId),
+    ];
     if (roles.length) visible.push(inArray(tasks.assigneeRole, roles));
     where = and(where, or(...visible))!;
   }
@@ -73,6 +78,7 @@ export async function createTask(
       title: input.title,
       assignee: input.assignee,
       assigneeRole: input.assigneeRole ?? null,
+      assigneeUserId: input.assigneeUserId ?? null,
       due: input.due,
       priority: input.priority,
       status: input.status,
@@ -100,6 +106,8 @@ export async function updateTask(
   if (patch.assignee !== undefined) set.assignee = patch.assignee;
   if (patch.assigneeRole !== undefined)
     set.assigneeRole = patch.assigneeRole ?? null;
+  if (patch.assigneeUserId !== undefined)
+    set.assigneeUserId = patch.assigneeUserId ?? null;
   if (patch.due !== undefined) set.due = patch.due;
   if (patch.priority !== undefined) set.priority = patch.priority;
   if (patch.patient !== undefined) set.patient = patch.patient ?? null;

backend/src/types/task.ts

@@ -11,6 +11,10 @@ export type Task = {
   assignee: string;
   // Department (member role) the task is assigned to; null = personal task.
   assigneeRole: string | null;
+  // A specific person the task is assigned to (user id); null when assigned to
+  // a department or kept personal. Takes precedence over assigneeRole for who
+  // sees the task.
+  assigneeUserId: string | null;
   due: string;
   priority: TaskPriority;
   status: TaskStatus;