Client-side fpRpc() is a drop-in for rpc() that automatically injects
tablet_tech_id from the tech_store into every action call. Read-only
endpoints can keep using plain rpc().
Server-side env_for_tablet_tech(env, tablet_tech_id) returns an env
scoped via with_user() when the id is a valid active user; otherwise
returns the original env unchanged. Controllers call this at the top
of action methods so all subsequent writes carry the right uid.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>