DCGW: Managed PII Sanitizer service

## Jobs to be done (optional)

## Definition of done
Josh: "still waiting for Eng to determine this architecture"

## Information
DRP: Josh W.
Aha: https://konghq.aha.io/epics/CGW-E-58
PRD: https://docs.google.com/document/d/1_M_FSlAqSUvpa6ItoMa_VD0dunmgpg0UPYflzIsYf8Q/edit?tab=t.0#heading=h.vc2v5ob2vz3n

## Due date (optional)

## Size

Start by reviewing the linked Aha epic and PRD to understand the proposed managed PII Sanitizer service. The issue is still waiting for Engineering to determine the architecture, so the implementation scope and definition of done cannot yet be established.

Written by the indexing model from the issue text.