Verification after commit d4c02a3 found Hono matching /:id BEFORE /activity
when the bare /api/agents/activity request hit the API — Postgres returned a
500 cast error because id='activity' was not a valid UUID.
Two changes:
1. Move GET /api/agents/activity registration to BEFORE GET /:id so Hono's
matcher picks the static path before the param path.
2. Add a UUID-format guard at the top of GET /api/agents/:id — returns
404 when id is not a UUID. Defense in depth: prevents future 500s if
a similarly-shaped static route collides with /:id.
Parent: t_e1cbd87d
Hermes
3847ef7b2d