fix(aggregate): filter before pagination, clamp limit, and return hasMore (closes #888)

[mopxam-art]

Overview

Closes #888 by ensuring the portfolio aggregate endpoint (/v1/projects/aggregate) applies filters across the full dataset prior to pagination, enforces positive limit boundaries clamped to 1–100, and returns hasMore and conditional cursor fields matching the standard pagination contract.

Problem & Motivation

Previously, /v1/projects/aggregate sliced project IDs first via Array.from({ length: limit }, (_, i) => cursor + i + 1) and then applied category/region filters to that slice. As a result, filtered responses returned fewer items than requested limit (or even 0 items) despite matching records existing in later offsets. Furthermore, limit <= 0 was not rejected, and the response always echoed cursor: cursor + limit without indicating if more matching items existed.

Changes

• src/routes/aggregate.ts:
  • Added input validation rejecting non-positive limit (<= 0) and negative cursor (< 0) with 400 Bad Request.
  • Clamped upper limit to 100.
  • Retrieved full registry size via getTotalProjects(), filtered the entire candidate pool across category and region, and then applied pagination slice [cursor, cursor + limit].
  • Response now returns total, filtered_total, limit, hasMore, and only returns cursor when hasMore is true, aligning with /v1/projects.
• src/__tests__/aggregatePagination.test.ts:
  • Added 102 comprehensive tests across all 5 dimensions (boundary clamping, combinatorics across solar/forest/wind and 4 regions, host variations, negative controls, and multi-page crawl stress tests).

Verification

• 102 unit tests pass cleanly (npx jest src/__tests__/aggregatePagination.test.ts --forceExit).
• TypeScript typecheck passes with 0 errors (npx tsc --noEmit).
• ESLint passes with 0 errors (npx eslint src/routes/aggregate.ts).
• Production build compiles cleanly (npm run build).