feat: add tenant and user management with migrations, handlers, and tests

- Implemented tenant and user management features including:
  - Tenant creation and management with associated migrations.
  - User creation and management with associated migrations.
  - Tenant membership management with associated migrations.
  - Platform user roles management with associated migrations.
  - Quota management with associated migrations.
  - Article and template management with associated migrations.
- Added HTTP handlers for templates and workspaces.
- Created tests for protected and public routes.
- Introduced a script to check tenant scope in SQL queries.
- Documented task plan for backend completion and frontend foundation.

server/internal/tenant/repository/queries/auth.sql

@@ -0,0 +1,20 @@
+-- name: GetUserByEmail :one
+SELECT id, email, phone, password_hash, name, avatar_url, status, created_at, updated_at
+FROM users
+WHERE email = sqlc.arg(email) AND deleted_at IS NULL;
+
+-- name: GetUserByID :one
+SELECT id, email, phone, password_hash, name, avatar_url, status, created_at, updated_at
+FROM users
+WHERE id = sqlc.arg(id) AND deleted_at IS NULL;
+
+-- name: GetTenantMembership :one
+SELECT id, tenant_id, user_id, tenant_role, created_at
+FROM tenant_memberships
+WHERE user_id = sqlc.arg(user_id) AND deleted_at IS NULL
+LIMIT 1;
+
+-- name: GetTenantMembershipByTenantAndUser :one
+SELECT id, tenant_id, user_id, tenant_role, created_at
+FROM tenant_memberships
+WHERE tenant_id = sqlc.arg(tenant_id) AND user_id = sqlc.arg(user_id) AND deleted_at IS NULL;