cleanup: remove stale wrappers and complete the progress event model

[blackopsrepl]

Problem

There are a few signs of unfinished API surface:

• load_or_fetch_simple is a hidden one-line wrapper over default config,
• RoutingProgress includes variants that are not fully wired into producers,
• matrix progress reporting currently emits only a very coarse update.

Why this matters

Small unused wrappers and half-wired event models add maintenance overhead and make the API feel less intentional.

Scope

• Remove or justify load_or_fetch_simple.
• Either emit EncodingGeometries / Complete consistently or trim the enum.
• Improve matrix progress granularity if progress reporting remains public.

Acceptance criteria

• No low-value wrapper remains without a clear use case.
• Progress events reflect actual operation phases end-to-end.
• Public reporting APIs are either complete or intentionally minimized.