782f845dc9
Fast path (DATE/TITLE/UPLOAD_DATE) pushes sort + paging into the DB via findAll(Specification, PageRequest) and enriches only the returned slice — 30× cheaper than enriching all 1500 matches when the user is only going to see 50. In-memory sort paths (SENDER/RECEIVER/RELEVANCE) keep their LEFT JOIN-friendly sort but now slice in-memory too, so enrichment still runs against the page slice only. Controller passes PageRequest.of(page, size) built from @RequestParam values. Plan-level "add @Validated" prerequisite comes in the next commit. All existing tests updated mechanically to pass a pageable argument (PageRequest.of(0, 10_000) as an "effectively unpaged" sentinel). Stubs that previously matched findAll(Specification, Sort) for the fast path now match findAll(Specification, Pageable) with PageImpl<>. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>