[BE-90] Standardize pagination across all list endpoints

[yusuftomilola]

Overview

List endpoints across modules use differing (or no) pagination conventions. Unbounded lists will eventually time out, and the frontend has to special-case each endpoint.

Tasks

• Define a shared PaginationQueryDto (page, limit with a hard max, sortBy, sortOrder) in common/.
• Define a shared PaginatedResponse<T> — { data, meta: { page, limit, total, totalPages, hasNext, hasPrev } }.
• Apply to every list endpoint; enforce a maximum page size (e.g. 100) server-side.
• Add @ApiOkResponse generic schemas so Swagger renders the wrapper correctly.
• Update frontend/lib/apiClient.ts and callers to the shared shape.

Acceptance Criteria

• Every list endpoint accepts ?page=&limit= and returns the standard envelope.
• Requesting limit=100000 is clamped, not honoured.
• Swagger shows the paginated wrapper for list routes.

Notes for Contributors

Comment below to be assigned.