Phase 1: ArrowSpace search backend

What's new

First production-ready release of arro-server.

4 search modes — all confirmed working

• POST /search — spectral tau-mode (graph-Laplacian)
• POST /search/energy — energy distance, supports custom k
• POST /search/hybrid — spectral + linear blend via alpha
• POST /search/linear — brute-force cosine sorted, supports custom k

Bug fixes

• search_energy / search_linear_sorted now pass k correctly to arrowspace
• search_hybrid signature cleaned (unused tau removed)
• Out-of-bounds GET /items/{idx} returns 404 instead of 500

Validation & testing

• All POST search endpoints return 422 on malformed input (Pydantic)
• Full test suite: adapter unit, HTTP integration, LRU cache, sidecar fallback

Stack

FastAPI · Zarr v3 · arrowspace · pydantic-settings v2 · Hatch