api(arweave): negative limit reaches SQL LIMIT and surfaces as 503 db_unavailable

[euxaristia]

Summary

GET /api/v1/arweave/anchors clamps only the top of the limit (crates/gitlawb-node/src/api/arweave.rs:28, q.limit.min(200)) and binds it straight into LIMIT $2 (db/mod.rs:3836). ?limit=-1 produces a database error that the bare ? mapping (#251) classifies as 503 db_unavailable.

Impact

A client-input bug surfaces as a database-availability error on an anonymous route, and negative values skip the intended pagination contract entirely. Cosmetic per the rubric.

Remediation

1. Clamp to [1, 200] like the sibling list endpoints (compare GET /api/v1/tasks: clamp limit to match siblings; negative limit returns 500 with raw DB error #399/Fix #399: GET /api/v1/tasks: clamp limit to match siblings; negative limit returns 500 with raw DB error #405).

Proposed labels: kind:bug, crate:node, subsystem:api.