Refactor all list APIs for server-side pagination, search, and sort

All list endpoints now return paginated responses:
  { data: [...], pagination: { page, limit, total, totalPages } }

Query params: ?page=1&limit=25&q=search&sort=name&order=asc

Changes:
- Added PaginationSchema in @forte/shared for consistent param parsing
- Added pagination utils (withPagination, withSort, buildSearchCondition,
  paginatedResponse) in backend
- Refactored all services: AccountService, MemberService, CategoryService,
  SupplierService, ProductService, InventoryUnitService
- Merged separate /search endpoints into list endpoints via ?q= param
- Removed AccountSearchSchema and ProductSearchSchema (replaced by
  PaginationSchema)
- Added pagination test (5 items, page 1 limit 2, expect totalPages=3)
- Updated CLAUDE.md with API conventions
- 34 tests passing

packages/shared/src/schemas/index.ts

@@ -1,3 +1,6 @@
+export { PaginationSchema } from './pagination.schema.js'
+export type { PaginationInput, PaginatedResponse } from './pagination.schema.js'
+
 export { UserRole, RegisterSchema, LoginSchema } from './auth.schema.js'
 export type { RegisterInput, LoginInput } from './auth.schema.js'