feat(api): add activities + work_sessions domain schema and shared contracts

packages/shared/src/index.ts

@@ -16,3 +16,50 @@ export const MeResponse = z.object({
   user: PublicUser,
 });
 export type MeResponse = z.infer<typeof MeResponse>;
+
+export const InsoleType = z.enum(['Kurk', 'Berk', '3D']);
+export type InsoleType = z.infer<typeof InsoleType>;
+
+export const Activity = z.object({
+  id: z.number().int(),
+  name: z.string(),
+  insole_types: z.array(InsoleType),
+  created_at: z.string(), // ISO-8601
+});
+export type Activity = z.infer<typeof Activity>;
+
+export const CreateActivityInput = z.object({
+  name: z.string().trim().min(1),
+  insole_types: z.array(InsoleType).default(['Kurk', 'Berk', '3D']),
+});
+export type CreateActivityInput = z.infer<typeof CreateActivityInput>;
+
+export const UpdateActivityInput = CreateActivityInput;
+export type UpdateActivityInput = z.infer<typeof UpdateActivityInput>;
+
+export const SessionStatus = z.enum(['active', 'completed', 'discarded']);
+export type SessionStatus = z.infer<typeof SessionStatus>;
+
+export const WorkSession = z.object({
+  id: z.number().int(),
+  user_id: z.string(),
+  activity_id: z.number().int(),
+  activity_name: z.string().optional(), // present on history/active joins
+  insole_type: InsoleType.nullable(),
+  pair_count: z.number().int(),
+  start_time: z.string(), // ISO-8601
+  end_time: z.string().nullable(),
+  duration_seconds: z.number().int().nullable(),
+  status: SessionStatus,
+  source: z.enum(['app', 'manual']),
+  notes: z.string().nullable(),
+  created_at: z.string(),
+});
+export type WorkSession = z.infer<typeof WorkSession>;
+
+export const StartSessionInput = z.object({
+  activity_id: z.number().int(),
+  insole_type: InsoleType,
+  pair_count: z.number().int().min(1).default(2),
+});
+export type StartSessionInput = z.infer<typeof StartSessionInput>;