docs: host apps should consume content search, time range, and sort params

[waterbro-8]

Summary

Companion to #68.

bytefolk/doc search is the API/database layer. Host apps (RoleWeave Memory & Collaboration, other embeddings) still need to:

• send query / keyword against body text, not title only
• pass after / before / sort
• render matchField once it exists

This issue tracks that host-app work so it is not lost when #68 closes on the doc API PR.

Suggested split

• RoleWeave: memory/docs plane search box and filters
• Other embeddings: follow the same query params on GET /api/v1/documents