feat(org): enforce tenant isolation in ws/kc with leave and stats APIs

Add org_id schema migrations and service-level filtering for teacher-student and class workflows, then cover org-context behavior with focused unit/e2e tests for leave and hour statistics.

Made-with: Cursor

htykc_models/migrations/2026-04-27-193300_add_org_id_to_kc_tables/down.sql

@@ -0,0 +1,20 @@
+drop index if exists idx_clazz_repeat_org_id;
+drop index if exists idx_hour_transaction_org_id;
+drop index if exists idx_course_hour_package_org_id;
+drop index if exists idx_clazz_attendance_org_id;
+drop index if exists idx_clazz_org_id;
+
+alter table clazz_repeat
+    drop column if exists org_id;
+
+alter table hour_transaction
+    drop column if exists org_id;
+
+alter table course_hour_package
+    drop column if exists org_id;
+
+alter table clazz_attendance
+    drop column if exists org_id;
+
+alter table clazz
+    drop column if exists org_id;

htykc_models/migrations/2026-04-27-193300_add_org_id_to_kc_tables/up.sql

@@ -0,0 +1,29 @@
+alter table clazz
+    add column org_id varchar;
+
+alter table clazz_attendance
+    add column org_id varchar;
+
+alter table course_hour_package
+    add column org_id varchar;
+
+alter table hour_transaction
+    add column org_id varchar;
+
+alter table clazz_repeat
+    add column org_id varchar;
+
+create index idx_clazz_org_id
+    on clazz (org_id);
+
+create index idx_clazz_attendance_org_id
+    on clazz_attendance (org_id);
+
+create index idx_course_hour_package_org_id
+    on course_hour_package (org_id);
+
+create index idx_hour_transaction_org_id
+    on hour_transaction (org_id);
+
+create index idx_clazz_repeat_org_id
+    on clazz_repeat (org_id);

htykc_models/migrations/2026-04-27-193400_create_clazz_leave_request/down.sql

@@ -0,0 +1 @@
+drop table if exists clazz_leave_request;

htykc_models/migrations/2026-04-27-193400_create_clazz_leave_request/up.sql

@@ -0,0 +1,34 @@
+create table clazz_leave_request
+(
+    id varchar not null,
+    org_id varchar not null,
+    clazz_id varchar not null
+        constraint clazz_leave_request_clazz_id_fk
+            references clazz (id),
+    student_id varchar not null,
+    teacher_id varchar,
+    leave_type varchar not null,
+    reason varchar,
+    request_status varchar not null default 'PENDING',
+    created_at timestamp not null default now(),
+    created_by varchar,
+    reviewed_at timestamp,
+    reviewed_by varchar,
+    is_delete boolean not null default false
+);
+
+create unique index clazz_leave_request_id_uindex
+    on clazz_leave_request (id);
+
+alter table clazz_leave_request
+    add constraint clazz_leave_request_pk
+        primary key (id);
+
+create index idx_clazz_leave_request_org_id
+    on clazz_leave_request (org_id);
+
+create index idx_clazz_leave_request_clazz_id
+    on clazz_leave_request (clazz_id);
+
+create index idx_clazz_leave_request_student_id
+    on clazz_leave_request (student_id);